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GENESYS

User's Guide

© Copyright 1986-2000

Eagleware Corporation635 Pinnacle CourtNorcross, GA 30071 USA

Phone: (678) 291-0995FAX: (678) 291-0971E-mail: [email protected]: http://www.eagleware.com

Printed 10/2000Printed in the USA

Table of Contents

Chapter 1: Main GENESYS Window....................................... 7

Main GENESYS Window....................................................7

Chapter 2: Workspace Window ............................................ 11

Workspace Window..........................................................11

Chapter 3: Tune Window ...................................................... 15

Overview ..........................................................................15 Adjusting The Tuning Percentage .....................................16 Reverting Tuned Values ...................................................16 Updating Tuned Values ....................................................17

Chapter 4: Templates............................................................ 19

Overview ..........................................................................19

Chapter 5: Designs: Schematics .......................................... 21

Overview ..........................................................................21 Creating a Schematic .......................................................22 Simulating a Schematic ....................................................27 Selecting Elements...........................................................31 Moving Elements..............................................................32 Deleting Elements ............................................................32 Zooming ...........................................................................33 Panning............................................................................33 Mirroring and Rotating Elements.......................................34 Adding Comment Text ......................................................34 Using Substrates ..............................................................35 Ports and Impedances......................................................35 Reusing Networks with the NET Block ..............................36 Changing a Model ............................................................36 Changing a Symbol ..........................................................36

Chapter 6: Designs: User Models ......................................... 39

Overview ..........................................................................39 Creating A Model..............................................................39

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Creating A Model Without An Existing Schematic.......39 Creating A Model From An Existing Schematic ..........40

User Model Example: A Self Resonant Capacitor ............. 41 Using A Model In SCHEMAX............................................ 47 Text Model Definitions...................................................... 47

Chapter 7: Designs: Text Netlists .........................................49

Overview.......................................................................... 49 Shunt-C Coupled Netlist Example .................................... 50 Substrates........................................................................ 52 Units In GENESYS........................................................... 53 Seeing Text Equivalents for Schematics........................... 53

Chapter 8: Designs: Layouts.................................................55

Basics.............................................................................. 55 Overview ...................................................................55 Creating A New Layout ..............................................55 Lines, Rectangles and Arcs .......................................57 Selecting Objects.......................................................58 Deleting Objects ........................................................60 Moving Objects..........................................................61 Using Object Handles ................................................61 Using Object Property Dialogs ...................................62 Cutting And Pasting...................................................63 Grouping Objects.......................................................64 Automatically Connecting Layout Objects ..................64 Default Text Font .......................................................65 Fonts And Text Objects .............................................65 Pads..........................................................................67 Viaholes ....................................................................68

Components & Associations............................................. 70 Components..............................................................70 Nodes and Rubber Band Lines ..................................71 Association Tables ....................................................72 Overriding Association Defaults .................................73 Association Table Maintenance .................................73 Automatic Transmission Line Generation...................74

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Statistics Window...................................................... 76 Converting A Component To A Group ....................... 76 Multi-Device Footprints.............................................. 77 Power And Ground Connections ............................... 79

Layers ..............................................................................79 Layer Table............................................................... 79 Hiding Layers............................................................ 80 Mirrored Layers......................................................... 81 .LYR Files ................................................................. 81

Polygons, Pours, and Ground Planes ...............................82 Polygons................................................................... 82 Poured Polygons....................................................... 83 Ground Plane Pours.................................................. 84

Chapter 9: Designs: Link to Spice File................................. 85

Overview ..........................................................................85 SPICE File Compatibility...................................................86

Chapter 10: Designs: Single Part Model .............................. 89

Overview ..........................................................................89

Chapter 11: User Footprints ................................................. 91

Overview ..........................................................................91 Layers In The Footprint Editor...........................................92 Loading And Merging Footprints .......................................92 Creating And Saving Footprints ........................................93 Renaming And Deleting Footprints....................................94 Placing Objects In The Footprint Editor .............................94 Placing Pads In The Footprint Editor.................................94 Placing Ports In The Footprint Editor.................................95 Creating Multi-Device Footprints .......................................95 Provided Footprint Libraries..............................................96 Footprint Example 1..........................................................97 Footprint Example 2........................................................100

Chapter 12: Simulations/Data............................................. 107

Simulations / Data ..........................................................107

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Which Simulator Should I Use? ...................................... 107 Linear ............................................................................. 107 Linear Simulation ........................................................... 111 Link To Data File............................................................ 111 Planar 3D Electromagnetic Simulation............................ 111 Parameter Sweep .......................................................... 112 DC Analysis Overview.................................................... 112 Harmonic Balance Overview .......................................... 113 HARBEC Popup Menu................................................... 114 Entering Nonlinear Models ............................................. 115 DC Analysis - Verifying Transistor Parameters ............... 116 DC Analysis - Biasing the Transistor............................... 120 Linear S-Parameter Simulation Example ........................ 122 HARBEC Analysis Walkthrough ..................................... 124 Linear vs. Nonlinear Device Models................................ 128 Typical Harmonic Balance Measurements...................... 128 Solving Convergence Issues .......................................... 129 Optimizing Simulation Performance................................ 130

Jacobian Calculation................................................130 Order vs. Accuracy and Time...................................131 Amplitude Stepping..................................................131 Krylov Subspace Iterations ......................................132

Chapter 13: Measurements (Output Parameters) ...............133

Overview........................................................................ 133

Chapter 14: Outputs ............................................................135

Overview........................................................................ 135 Creating an Output......................................................... 135 Opening an Existing Output............................................ 136 Property Dialogs ............................................................ 136 Markers.......................................................................... 136 Zooming On Smith And Polar Charts.............................. 138 Annotating Graphs ......................................................... 139 Rectangular Graphs ....................................................... 141 3D Graphs ..................................................................... 142 Smith Charts .................................................................. 144

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Polar Charts ...................................................................145 Variable Viewer ..............................................................147 Tables ............................................................................148

Chapter 15: Equations ........................................................ 151

Equations .......................................................................151 Entering Equations .........................................................151 Viewing Variable Values .................................................151 Bandpass Filter With Equations ......................................151

Chapter 16: Substrates ....................................................... 155

Overview ........................................................................155

Chapter 17: Optimization .................................................... 157

Overview ........................................................................157 Entering Targets.............................................................158 Starting Optimization ......................................................160 Objective Function..........................................................160 Weights ..........................................................................162

Chapter 18: Yield/Statistics ................................................ 163

Overview ........................................................................163 Entering Targets.............................................................163 Variable Setup................................................................165 Monte Carlo Example .....................................................165 Worst Case vs. Monte Carlo ...........................................169 Sensitivity Analysis .........................................................169 Design Centering............................................................170 Yield Optimization...........................................................171 Monte Carlo Report ........................................................172

Chapter 19: Entering Notes ................................................ 173

Overview ........................................................................173

Chapter 20: Exporting Files ................................................ 175

Overview ........................................................................175 Exporting to Spice ..........................................................176

Chapter 21: Using Files from Earlier GENESYS Versions. 181

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Using Files From Earlier GENESYS Versions................. 181

Chapter 22: Keyboard Commands ......................................183

General Keystroke Commands....................................... 183 Graph Output Keystroke Commands.............................. 184 =LAYOUT= Keystroke Commands................................. 184 SCHEMAX Keystroke Commands.................................. 184

Chapter 1: Main GENESYS Window

Main GENESYS Window

A sample GENESYS main window is shown below. Click on any part of this window to go to help on that item.

In GENESYS version 7, many new features have been added to the environment. Some of these interface enhancements are:

y Dockable schematic and layout toolbars (2,3,5,10)

y Dockable Tune Window (4)

y Arbitrary tuning percentage

y Workspace Window for easy design navigation (9)

y Notes section for easy design documentation

y Real tables for tabular display (13)

y Easier user model entry from existing schematics (6)

y Windows 2000 style interface using the newest Microsoft Foundation Class technology

Main GENESYS Window

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y Send a design file as email right from the File menu (1)

y New design templates make it easy to reproduce common designs

y Unlimited undo/redo levels in SCHEMAX and =LAYOUT=

y Tip of the Day contains dozens of tips for both new and experienced GENESYS customers

y Improved help files

y Powerful post-processing allows direct calculations with simulation data

y Open multiple files simultaneously

y No more juggling multiple files per design - create multiple schematics/layout in one design

y Long, descriptive names for schematics, simulations, layouts, and graphs

y Right mouse button pops up menus for quick local changes

y Define and use custom functions and data

y Real time zooming on Smith and polar charts

y More flexible markers on graphical charts

y Improved Smith Chart (8)

y Unlimited number of graphs (7)

y Unlimited number of traces on each graph

y Annotation objects on graphs for easy documentation

y Simple Copy/Paste for getting images into desktop publishing programs

y Impedance and admittance grids on Smith charts

y Fully customizable graphs (7)

y Plot data directly from files without building a schematic

y New auto-connect in =LAYOUT= snaps rubber-banded connections together (11)

y Intelligent simulation only simulates the portions of the design that have changed since the last calculation

Main GENESYS Window

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y Port impedances can be tuned, swept, or optimized

y Improved radial stub model

y EMPOWER now supports multi-level EM simulation

y EMPOWER supports thick metal layers

Items on the main screen:

1. Menus

2. Toolbars

3. SCHEMAX Toolbar

4. Tune Window

5. Lumped Toolbar

6. Designs: Schematics

7. Rectangular Graphs

8. Smith Charts

9. Workspace Window

10. Microstrip Toolbar

11. Designs: Layouts

12. Equations

13. Tables

14. Variable Viewer

15. Status bar

Not Shown: 3D Graphs Polar Charts Footprint Editor Optimization EMPOWER

Chapter 2: Workspace Window

Workspace Window

Note: Be sure to try right-clicking in the Workspace Window. This is the easiest way to do most operations withing GENESYS.

The GENESYS Workspace Window is an "organizer" for all loaded files. An example is shown below:

The Workspace Window contains a common Windows control known as a tree control. This is the same type of control used in the Windows Explorer, and in many email browsers.

Workspace Window

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A tree control is a window that displays a hierarchical list of items, such as the entries in an index, or the files and directories on a disk. Each item consists of a label and an optional bitmapped image, and each item can have a list of subitems associated with it. By clicking an item, the user can expand or collapse the associated list of subitems.

The Workspace Window is organized as follows:

y Designs/Models contains schematics, layouts, netlists, user models, spice model file links and single part models.

y Simulations/Data contains linear simulations, DC Analyses, Harmonic Balance (HARBEC) Simulations, EMPOWER simulations, parameter sweeps, and linked data files.

y Outputs contains any data output, whether graphical or tabular.

y Equations contains global equations, which are used in schematics or netlists, or can plotted directly.

y Substrates contains any substrates used in the current design.

y Optimizations contains optimization goals that have been set up for the current design.

y Yield contains yield goals that have been set up for the current design.

y Notes is a text editor for adding comments or suggestions for the current design.

To show any workspace item's menu:

y Right-click the item in the workspace.

To delete an item:

y Right-click the item and choose "Delete", or

Select the item and press the Delete key.

Note: The main nodes in the tree control (Designs, Equations, etc.) cannot be deleted or renamed.

To rename an item:

y Right-click the item and choose "Rename".

Workspace Window

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To open an item (display its window):

y Double-click the item, or

y Select the item and press "Enter".

To open or close a folder (Designs, Simulations/Data, etc.):

y Double-click the folder, or

y Click the "+" or "-" to the left of the folder, or

y Select the item and press Enter.

Items can be created by right-clicking the main node and choosing the desired item to create. For example, to create a new schematic, right-click the Designs node and choose "Add Schematic".

Chapter 3: Tune Window

Overview

One of the most powerful features of SuperStar is real-time tuning of values in your circuit file. The Tune Window is used to quickly adjust previously marked (with '?') parameter values. The first time GENESYS is started, the Tune Window is at the left edge of the screen. An example Tune Window is shown below.

You can use tunable values almost anywhere in GENESYS: schematics, netlists, substrates, and port impedances for example. To make any value tunable place a question mark (?) in front of the value. To make multiple values tunable in a schematic, select "Make Tunable" from the Schematic menu. See almost any example for tune values.

The commands for tuning are:

y Page Up - tunes the selected value UP by the current tuning percentage.

y Page Down - tunes the selected value DOWN by the current tuning percentage.

y F5 - Updates dashed traces

y Shift+F5 - Reverts to the "original" values (the values corresponding to the dashed traces.)

y F6 - Decreases the tuning percentage.

Tune Window

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y F7 - Increases the tuning percentage.

y Arrow Keys - selects the next variable for tuning.

See Also: Adjusting The Tuning Percentage Reverting Tuned Values Updating Tuned Values Equations Overview

Adjusting The Tuning Percentage

The tuning percentage is shown as the first cell in the Tune Window, as shown above. This controls the amount values will be stepped when tuning.

Whenever a parameter is tuned up or down, the tuning percentage is used to calculate the new parameter value.

To change or adust the tuning percentage:

1. Type a new value into the "Tune %" cell of the Tune Window

or

2. Press F6 to decrease the tuning percentage by a factor of 2.

3. Press F7 to increase the tuning percentage by a factor of 2.

The default tuning percentage is 5%.

Reverting Tuned Values

If values have been tuned, but you wish to return to the previous values:

y Choose Actions/Revert To Dashed Traces, or

y Press Shift-F5.

This reverts to the most recent untuned values, and updates all data displays to the original data.

Updating Tuned Values

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Updating Tuned Values

To update all variables to the tuned values, select Update Dashed Traces from the Actions menu, or press F5. This is very useful for saving a better set of values you have found while tuning or optimizing.

Chapter 4: Templates

Overview

Templates are a very convenient way to get started quickly with a new workspace. Templates give you a complete circuit as your starting point that you just need to modify for your specific application. Many templates are included with GENESYS, and you can easily add your own. As of the writing of this manual, GENESYS included the following templates:

y Default.WSP - Just includes a blank schematic. The Default.WSP template is automatically loaded whenever a new workspace is created. You may want to save your favorite setup over this template.

y Filter.WSP - Passband and stopband response of a filter. Includes a schematic, 2 linear simulations, 2 rectangular graphs, and a Smith Chart.

y Loop Oscillator.WSP - Open loop analysis of an oscillator. Includes a schematic, a linear simulation, 2 rectangular graphs, and a Smith Chart.

y Model Extract.WSP - A sophisticated template for device modeling using optimization to make the response of a schematic model identical to the response of a data file. Includes a schematic, a link to a data file, a linear simulation, 2 polar charts, 2 Smith Charts, a table, post-processing equations, and a set of optimization targets. See the example "Model Extract.WSP".

y Neg R Oscillator.WSP - For simulating negative resistance oscillators. Includes a schematic, a linear simulation, and a rectangular graph.

y Stability.WSP - Setup for stability analysis of an active circuit. Includes a schematic, a linear simulation, 2 Smith Charts for circles, a table, and post-processing for calculating MU (a stability parameter). This circuit is also an excellent example of post-processing and user functions.

y View S Data.WSP - Setup to display S Parameters and noise on graphs and a table. Includes a schematic, a

Templates

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linear simulation, a rectangular graph, a polar chart, a Smith Chart, and a table.

y BJT NL Model Fit.WSP - A template to verify the nonlinear characteristics of a bipolar transistor and to optimize package parasitics to match the nonlinear model to measured S-parameters. Insert a bipolar model, including package parasitics. The template will then analyze the DC curves of the device, S-parameters, single-tone performance, and two-tone intermodulation.

To use a template, simply select "New from Template..." from the File Menu. To add a template for future use, simply save any workspace into the \EAGLE\TEMPLATE directory with the rest of our templates. You may also make modifications to any of our templates, but be careful not to accidentally overwrite the templates if you re-install GENESYS.

Chapter 5: Designs: Schematics

Overview

Most engineers will prefer to use SCHEMAX to enter circuits. Schematics allow for easier design documentation and verification than text circuit files. This chapter describes how to enter a design using SCHEMAX.

NOTE: If you have not purchased SCHEMAX, you may still use it in demo mode, but you cannot save or print your files. If you would like to purchase SCHEMAX, please contact Eagleware for an authorization code.

There are 2 ways to create a new schematic:

With the Workspace Window:

1. Right-click on the Workspace Window "Designs/Models" node.

2. Click "Add Schematic".

3. Name the new schematic.

With the Design Manager:

1. Open the Design Manager by choosing "Designs/Models..." on the Workspace menu.

2. Click the "New" button.

3. Select "Add Schematic".

4. Name the new schematic.

To edit an existing schematic:

From the Workspace Window:

y Double-click the desired schematic under the "Designs/Models" node.

From the Design Manager:

y Double-click the desired schematic in the list, or

y Select the desired schematic and click the "Open"

Designs: Schematics

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button.

Creating a Schematic

This section illustrates how to create and simulate a bridge-t circuit, as shown in the figure below.

SCHEMAX is designed to be quick and easy to use. Once you have followed this example, you will be able to enter your own schematic.

NOTE: If at any time you make a mistake, select Edit/Undo to "undo" the last operation.

To enter the schematic:

1. Select "New" from the File menu. This creates a new workspace, and a blank schematic appears.

2. The screen should now look like the figure below.


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3. Right-click the "Sch1 (Schematic)" node under "Designs/Models" in the Workspace window as shown in the figure below.

4. Select "Rename", and name the schematic "Bridge-T". The schematic window now shows "Bridge-T" as the schematic title.

Designs: Schematics

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5. The Main SCHEMAX toolbar appears whenever a schematic window is selected. In the figure above, this toolbar is located below the main toolbar.

6. Press the "Lumped" button on the Components toolbar to open a new toolbar containing lumped elements. The Lumped toolbar is shown in the figure below.

Note: Whenever the mouse cursor is placed over a toolbar button, a prompt appears showing the function for that button. This is illustrated for the Resistor button in the figure above.

7. Press the Resistor button.

8. Click and hold the left mouse button inside the schematic grid area. Drag the mouse to the right and release the button. A resistor appears.

Note: When a part is initially placed, it will be drawn using a purple highlight if the part is not fully defined. In other words, you need to enter all of the required parameters (such as resistance) to see the part in its normal colors. Any unconnected terminals will also be marked with purple circles. These features are designed to help you spot potential problems in your schematic as early as possible. The purple highlights are not shown when printing or copying to the clipboard.

9. Press the space bar. This reselects the resistor button.

Tip: The space bar can always be used to repeat the last part placement. If the space bar is pressed repeatedly, SCHEMAX will cycle through the components that have been placed.


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Tip: The R key may also be used to place a resistor. After pressing the R key, use the left mouse button to place the part. See the Quick Reference Card for a list of shortcuts.

10. Click the left mouse button inside the circle on the last resistor’s right terminal, drag to the right and release the mouse button. A second resistor appears, connected to the first resistor. Be sure to click very close to the resistor's terminal, so that the parts actually snap together.

11. Press the Capacitor button on the toolbar.

Tip: The C key may also be used to place a capacitor.

12. Click and drag to place the capacitor above the two resistors, as shown in the figure below. Note that the capacitor is not yet connected to the resistors.

13. Next, we will connect the capacitor:

a. Click the 90° button ( ) to place a 90º connection.

Tip: The W key may also be used to place a 90° wire.

Designs: Schematics

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b. Click on the left node of the first resistor, drag the connection to the left node of the capacitor and release the mouse button.

Note: Be sure to drag up first (before dragging left) to orient the connection properly.

c. Press the space bar to place another 90° wire and click and drag from the capacitor’s right node to the right node of the second resistor.

Note: Be sure to drag right first (before dragging down).

14. Place the inductor by pressing the Inductor button, then clicking and dragging downward from between the two resistors.

15. Place the ground by pressing the Ground button, then click and drag downward from the inductor’s bottom terminal.

16. Press the Input button ( ). Select "Input: Standard (*INP)". Click and drag from right-to-left starting the left terminator of the left resistor and release the mouse button. The Input dialog appears. Press OK.

17. Place the output by clicking the Output button ( ). Click and drag to the right from the right resistor and release the mouse button.

Tip: The key for Inductor is L, Ground is G, Input is I, and Output is O.

Note: For your circuits, be sure to enter any required termination impedances or filenames into the port prompts..

The drawing of the schematic is now complete. This would be a good time to save your file by selecting "Save" from the File menu. Next, the component values must be entered:

18. Select the capacitor you have drawn by clicking on it once.

19. Select "Parameters" from the Edit menu (or press Enter). This will open the capacitor’s property dialog box.

Simulating a Schematic

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Tip: Double-clicking on an element will also open the Element Properties dialog box.

20. Type 47 into the Capacitance field. Leave the Designator field as C1 and the Capacitor Q field empty. Schemax will normally create auto-designators, such as C1. The auto-designator feature can be turned off in the Options dialog box, if you prefer to name your own parts.

21. Press OK to close the dialog box.

22. Open the left resistor’s dialog box (as above). Type 50 into the Resistance box and press OK. Repeat for R2 (the right resistor) and assign it a value of 50 also.

23. Open the inductor’s dialog and assign it a value of 120.

Tip: After you have finished creating a schematic, you find that your parts are labeled somewhat haphazardly. You can use Edit / Select All (Ctrl + A) followed by Schematic / Reapply Auto-Designators to relabel all your parts using an intelligent, left-to-right ordering. You may also wish to use Schematic / Renumber Nodes to reorder all your net node numbers using the same easy to read left-to-right ordering.


In this section, we will show how to simulate a previously entered schematic.

Designs: Schematics

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1. In the Workspace Window, right-click on Simulations/Data and choose "Add Linear Simulation".

2. Accept the default name by clicking OK.

3. Enter the following values in the "Linear Simulation Properties" dialog:

Type of Sweep: Linear: Number of Points Start Freq (MHz): 10 Stop Freq (MHz): 200 Number of Points: 11

4. Click OK.

Now, an output has to be created to display the simulated schematic.

5. Right-click on the "Outputs" node in the Workspace window as shown below.


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6. Choose "Add Rectangular Graph".

7. Accept the default name by clicking OK.

8. The Graph Properties dialog appears.

9. Enter data as shown in the figure below. Set measurement 1 to S21, set measurement 2 to GD[S21] with the Y-Axis on the right, and click OK.

Designs: Schematics

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Note: The data shown in the figure below requests a plot of S21, and the group delay of S21. For information on the measurements available for plotting, see the Measurements section of the Reference manual.

You should now see a graph similar to the one shown below.

If you receive an error message or want to change the response type, double-click anywhere in the graph area to display the Graph Properties dialog.

Selecting Elements

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Selecting Elements

Objects must be selected before they can be manipulated. An object is shown in red when it is selected.

To select a single element:

1. Be sure that no buttons on the tool bar are highlighted. (If any are highlighted, press Esc.)

2. Click on the element to select with the left mouse button.

To select multiple elements by drawing a rectangle around them:


2. Click and hold the left mouse button in an open space on the schematic. If there is no open space, click the Zoom To Rectangle button ( ) before dragging.

3. Drag the mouse until a box is drawn which completely surrounds the items to be selected.

4. Release the mouse button.

To individually select multiple elements:


2. Hold down the Shift key while clicking on elements to add to your selection (the Windows standard.)

3. Hold down the Ctrl key while clicking on elements to add or remove to your selection. The Windows standard works like this: If the item is not selected when you Ctrl+click it will selected, otherwise it will toggle to the unselected state.

Tip: Once a selection has been created, you can place it on the Windows clipboard using Edit / Copy and then paste it into other applications like Microsoft Word.

To select an element which is behind other elements:


2. Click on the element to select with the left mouse button.

Designs: Schematics

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3. Continue clicking in the same spot until the desired element is selected. Do not click too fast (a double-click), or the element dialog box will be displayed.

4. Another way to select parts that are partially overlapping is to use the rectangle selection method above (for selecting multiple elements.) You can select a single element out of a group by surrounding just on item.

Moving Elements

Once an object is selected, you can move it using the mouse or arrow keys.

When moving parts with a mouse, watch the small green block, which shows the active terminal that "snaps" to connections and grid points. When you move parts that are connected, the components will remain connected if you have the Keep Connected global option enabled. Holding the ALT key down before you start the drag will temporarily toggle the Keep Connected setting.

When moving parts with the arrow keys, you need to press the Enter key to place the parts in their final location.

Once you have finished the drag operation, the connecting wires will be connected and merged to complete the circuit. Watch for the blue circles that briefly mark the spots where wires are connected; these connections will normally be shown as a black dot. If there is no black dot, the lines simply pass over one another and will not connect electrically in your simulations.

To move the text block associated with a part, first select the part, then left-click inside the text block. Use the mouse or arrow keys to move the text block, which will be aligned to the nearest quarter grid unit.

Tip: To stretch an existing wire, grab an endpoint and drag it to its new location.

Deleting Elements

To delete elements from the schematic:

1. Select the element(s) which you want to delete.

Zooming

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2. Press the Delete key, or choose Delete from the Edit Menu.

Zooming

There are two ways to zoom on a schematic:

1. Using the toolbar Zoom buttons:

Zoom In Zoom Out Zoom To Fit Zoom To Page Zoom To Rectangle

2. Using the keyboard:

Zoom In Ctrl + Page Up + (plus key)

Zoom Out Ctrl + Page Down - (minus key)

Zoom To Fit Ctrl + Home Z

Zoom To Page Ctrl + End

Zoom To Rectangle X

Zoom To Fit With Margin Shift + Z

NOTE: As you zoom out, SCHEMAX will selectively skip drawing excessive details. This is intentional; it is similar to using a street atlas, a state map, and a world map. Only the appropriate details are shown at a particular zoom setting. Text that would obscure your schematic is dropped and the remaining (more important) text is drawn extra large so that it is still readable even though you are zoomed out. Only the on-screen view is modified, the actual schematic is unchanged.

Panning

There are two ways to pan (scroll) a schematic:

1. Using the scroll bars.

2. Using the keyboard:

Designs: Schematics

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Pan Left Ctrl + Left Arrow

Pan Right Ctrl + Right Arrow

Scroll Up Ctrl + Up Arrow

Scroll Down Ctrl + Down Arrow

Mirroring and Rotating Elements

You may want to mirror the position of the labels and the elements. To do so, select an element with the mouse. Select Mirror, Rotate, or Rotate Counterclockwise from the Edit Menu until the element is in the desired position. There are a maximum of four positions to choose from.

Note: Mirroring is most important for changing the orientation of components like a bipolar transistor and operational amplifi ers.

Tip: The F6 key will mirror the selected part. F3 will rotate it. Shift + F3 will rotate it counterclockwise.

Tip: Mirroring can be used to flip the text box to the other side of simple (two lead) components such as resistors and capacitors.

Adding Comment Text

Text can be placed on the schematic by selecting the Text button ( ) from the main SCHEMAX toolbar. You must specify whether you want to justify the text to the left, center or right. Then click with the mouse at the position where you want the text placed. A box is displayed for typing the desired text.

Tip: You can also use the T key to create a left-justified text block.

Using Substrates

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Using Substrates

If your schematic contains any elements which use a substrate (such as microstrip, slabline, stripline, coax, and waveguide), you must add one or more substrates to your workspace before it can be analyzed. See the Substrate section of this User's Guide for more details.

Ports and Impedances

All schematics must have ports. These ports must be unique and be numbered sequentially. They correspond directly to the port numbers used in measurements. Ports are entered using the input ( ) and output ( ) buttons on the SCHEMAX Toolbar. The standard *INP and *OUT ports have three parameters:

y Designator - For documentation only; not currently used by any simulators. Note: Previous versions of GENESYS used this field to name networks. Now, network names are shown in the Workspace Window.

y Port Number - Identifies the port number for measurements. This value cannot be tuned.

y Port Impedance/Filename - Contains a port impedance or a filename. Specify either a terminating resistance value/equation or a filename containing frequency-dependent one-port device data. Since this field may contain either numbers or a filename, you must use an equal sign (=) in front of the entry if you want to use an equation expression or variable name. For example, enter "=Z" to use the value from variable Z. You may specify a tunable value such as "?50".

y SCHEMAX will automatically number nodes to match an attached port.

There are Input sources available as well: INP_VDC, INP_IDC, INP_VAC, INP_IAC, INP_PAC, INP_VPULSE, INP_IPULSE, INP_VPWL, and INP_IPWL.

Tip: Input ports can be created using the I key and Output ports can be created with the O key.

See "Matching\Ill Behaved Load.WSP" for an example which uses complex port termination files.

Designs: Schematics

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Reusing Networks with the NET Block

Sometimes it is necessary to refer to a schematic design within another schematic. This is done by using a "NET" block.

The symbols for reusing designs are accessed from the NET button. To reuse a network:

1. Press the Net button ( ) on the SCHEMAX toolbar.

Select the number of ports on the network to be reused.

2. Click and drag to place the NET symbol on the schematic.

3. Double-click the NET symbol to open the part dialog box, and enter the schematic’s name to reuse.

See "Balanced Amp.WSP" for an example which uses the NET block.

Changing a Model

Switching symbol models allows custom-created models to use the standard schematic symbols in SCHEMAX.

For example, if have an stripline interdigitated capacitor model, you could use the normal capacitor symbol. In this case, you would:

1. Place a lumped capacitor in the schematic.

2. Display the capacitor’s part dialog (double-click the part or select the part and press F4).

3. Click the Model button. The model dialog appears.

4. Select your interdigital stripline model from the list and click OK.

Changing a Symbol

Switching symbols allows access to additions symbols from within SCHEMAX for documentation purposes (these symbols, such as MIXER cannot be simulated as a single component.) You should build a sub-circuit to model a mixer.

For example, if you need to place a MIXER in your schematic as part of your final documentation, you should:

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37

1. Place a part with 3 connections like NET2 in the schematic (because a mixer has 3 connections.)

2. Display the net2’s part dialog (double-click the part or select the part and press F4).

3. Click the Symbol button. The symbol dialog appears.

4. Select the mixer symbol from the combo-box and click OK.

5. Then select your custom mixer model (sub-circuit) using the Model button. Follow the Changing a Model instructions.

Chapter 6: Designs: User Models

Overview

User models allow the creation of new elements by the user. These models behave just as if they were built into GENESYS. This capability is one of the more powerful features in GENESYS.

To create a new model, you must generally know three things:

1. An equivalent circuit for the model.

2. Equations which define the component values in the equivalent circuit.

3. The parameters that will be specified (if any) each time that the model is used. You can name and give descriptions for each of parameters.

A model can be created from any existing schematic or from scratch.

For more information, see Creating A Model.

Creating A Model

Note: You must have purchased SCHEMAX to create and save a schematic model. If you have not, you may create a text model definition using the process described later in the chapter.

There are 2 ways to create a new model:

1. Without an existing schematic.

2. From an existing schematic of the model.

Creat ing A Model Without An Existing Sch ematic


1. Right-click on the Workspace Window "Designs" node as shown in the figure below.

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40

2. Click "Add User Model (Schematic)".

3. Name the new model. Continue with step 5 in the Model Example below.




3. Select "Add User Model (Schematic)".

4. Name the new model. Continue with step 5 in the Model Example below.

For more information on how to use the Workspace Manager dialogs, see the Reference manual.

Creat ing A Model From An Existing Sch ematic

To create a model from an existing schematic:

1. Follow the instructions in "Creating A Model Without An Existing Schematic" above to create a blank model schematic.

Note: You do not have to define model parameters when the Model Properties dialog appears. By clicking OK, you can continue to create the model. However, the parameters (if any) must be defined, and a =LAYOUT= association chosen before the model can be used in a design.

2. Copy the existing schematic by selecting the entire schematic and choosing "Copy" from the Edit menu.

User Model Example: A Self Resonant Capacitor

41

3. Paste the copied schematic into the model window by selecting the window and choosing "Paste" from the Edit menu.

4. Copy any equations from the Global Equations window by selecting them and choosing "Copy" from the Edit menu.

5. Right-click the model in the Workspace Window. (See the figure below.)

6. Choose "Edit Model Equations".

7. Paste the equations into the model by selecting the Model Equations window and choosing "Paste" from the Edit menu.

The model has now been created. If you chose to save the workspace into the MODEL directory, the model will load automatically each time GENESYS is started. This is the recommended method to share models with others.


This example describes how to create a model for a self-resonant capacitor.

Note: This example assumes that you are familiar with drawing schematics and entering parameters.

The figure below shows the model used in this example along with its equations.


42

To create this model:

1. Create a new workspace by selecting "New" on the File menu.

2. Right-click the Designs/Models node in the Workspace Window as shown below:

3. Select "Add User Model (Schematic)".

4. Name the model "Self_Resonant_Capacitor".

Note: Spaces are not allowed in model names, so it is important to use the underscore character( _ ) as shown. It is next to the zero on most American keyboards (with shift).


43

5. The following dialog appears:

6. If you answer "Yes" to this dialog, GENESYS will automatically load the model in the future, making it available for quick use.

7. In the Model Properties dialog, enter the following information:

This box lists the parameters which must be passed to the model whenever it is used. The parameters for this example are:

C - the actual capacitor value. F0 - the frequency at which the capacitor self-resonates. Q - the quality factor of the capacitor.

The "Layout Association" box associates this model with a normal capacitor when choosing footprints for board layouts.

8. Press "OK" to close the Model Properties dialog.

9. Draw the schematic as shown in the figure below.


44

10. The inductor Q can be left blank, which defaults the value to 1 million. The capacitor Q should be set to "Q", which is one of the model parameters entered into the Model Properties dialog in step 5.

11. Right-click on the model in the Workspace Window as shown below.

12. Choose "Edit Model Equations".

13. Enter the equations as shown below:

14. This completes the model creation. Choose "Save" from the File menu to update the model file.

Next, let's create a schematic using the new model.

15. Choose "New" from the File menu.

16. Draw a schematic consisting of only an input, a series capacitor, and an output, as shown below (don't set any parameters yet):

17. Double-click the capacitor symbol to display its Properties dialog.


45

Click the Model button to open the Change Model dialog.

18. Set the category to SELF_RESONANT.wsp (or <All> to see every available model.) Then change the model to SELF_RESONANT_CAPACITOR as shown below, and click OK.

20. Now, the capacitor dialog changes to contain all the new model parameters, as shown below.

21. Right-click on the Simulations/Data node in the Workspace Window as shown below:

22. Add a linear simulation, and enter the parameters as shown below:


46

23. Right-click the Outputs node in the Workspace Window, as shown below:

24. Add a rectangular graph, and plot S11. The figure below shows the plot from this example. This plot of S11 shows a return loss minimum at 1500 MHz, the capacitor's self resonant frequency.

Using A Model In SCHEMAX

47

Using A Model In SCHEMAX

You can replace any element with a user defined model in SCHEMAX. To do this:

1. Double-click on an existing symbol that you have already drawn to change its model.

2. Press the Model button.

3. Choose the model to use from the combo box. An example is shown below.

4. Press OK.

5. Enter the parameters required for the model and press OK.

Text Model Definitions

Note: The preferred method for creating models is to use the schematic based model


48

editor described in User Model Example: A Self Resonant Capacitor.

If you do not have SCHEMAX, you may create a text description of your models. The format is as follows:

MODEL name(parm1,parm2,...) [model equation lines] [model description lines] DEFnP node1 node2...noden name

where:

y name is the name of the model

y parmn are the parameters specified by the user

y model equation lines contain the equations for the model

y model description lines contain elements which make up the model

y n is the number of external nodes on the model

y noden are the external nodes used in the model descriptionlines

The text equivalent for the model given in \EAGLE\MODEL\VARACTOR.WSP is:

MODEL VARACTOR(Vt,Co,Gamma,Lp,Cp,Q) Cv=Co/(1+Vt/0.6)^Gamma C4=Co/(1+4/0.7)^Gamma Rs=1/(3.14168e8*C4*1E-12*Q) CAP 1 2 C=Cv RES 2 3 R=Rs CAP 1 3 C=Cp IND 3 4 L=Lp DEF2P 1 4 VARACTOR

This model can be typed or copied into a text file. You must then edit the DEFAULT.MOD file in the \EAGLE\BIN directory: Add the line LIBRARY filename, where filename is the complete path and filename of your model. It can then be used as follows:

VARACTOR n1 n2 V=x Co=x G=x Lp=x Cp=x Q=x

Chapter 7: Designs: Text Netlists

Overview

In GENESYS, text files can be used instead of schematic files. These text files are often referred to as a "netlist" or "nodal netlist", since they describe a network's nodal connections. There are 2 ways to create a new netlist:


1. Right-click on the Workspace Window "Designs/Models" node as shown in the figure below.

2. Click "Add Text Netlist".

3. Name the new netlist.




3. Select "Add Text Netlist".

4. Name the new netlist.

To edit an existing netlist:


1. Double-click the desired netlist under the "Designs/Models" node.


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50

1. Double-click the desired netlist in the list, or

2. Select the desired netlist and click the "Open" button.


Shunt-C Coupled Netlist Example

Writing GENESYS circuit files is best understood by considering a few simple rules.

y There should be no floating nodes. In other words, EVERY node should have a path to ground.

y 0 is always datum node (ground).

y The DEF2P code connects all the elements between the specified input and output nodes.

The example circuit file, "Shunt C Netlist.WSP", is one of many example circuit files included with GENESYS. The schematic of this network and the netlist are shown below. We will now examine this circuit in detail. The schematic (not included in workspace) for a Shunt-C coupled LC resonator is shown below.

The figure below shows the GENESYS screen for "Shunt C Netlist.WSP".

Shunt-C Coupled Netlist Example

51

The first line is:

TERM(50)

This indicates that the circuit will be terminated in 50 ohms on all ports. For unequal terminations, the port impedances can be separated by commas. For example, if the source impedance was 25 ohms and the load was 75, the following line would be used:

TERM(25,75)

For complex or frequency dependent terminations, a filename can be used in place of a number. For example, to use 50 ohms at the input of a two-port and ANTENNA.RX at the output, use the following statement:

TERM(50,ANTENNA.RX)

Note: This assumes that ANTENNA.RX is in the same directory as the workspace. If it is not, you must specify a complete path in the TERM statement.

The second line in the netlist is:

CAP 1 0 C=47 Q=1000 NAME=C1


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This line describes a capacitor (CAP) connected between nodes 1 and 0 (0 being ground). The schematic above shows a picture of these connections. The capacitor has a value of 47pF (C=47) and a Q of 1000 (Q=1000). (Q is optional and defaults to 1 million if not specified.) This component is named C1 (NAME=C1). Names are optional but they can be useful when making multiple components with identical paramenters as was done later in this file.

SLC 1 2 L=1340 C=2 QL=120 QC=1000

This line specifies a Series L-C network (SLC) connected between nodes 1 and 2. Since this network defines both the inductor and the capacitor, node 5 shown in the schematic above is not needed. The inductor is 1340nH (L=1340) with a Q of 120 (QL=120) and the capacitor is 2pF (C=2) with a Q of 1000 (QC=1000). This component is not named since it will not be reused later.

C1 2 0

This line reuses (makes a duplicate of) capacitor C1. This could have been another CAP, but creating identical parts has two advantages. First, editing the circuit file to change the first occurrence of a component automatically changes the duplicate parts. Second, circuit analysis is faster.

DEF2P 1 2 RESONATE

This line finishes the description of the resonator network. It reduces the components described above to a two-port network. Node 1 is the input of the circuit and node 2 is the output. The defined network is assigned the name “RESONATE”.

Each network that you define must end with a DEFnP line, where n is the number of ports on the network. If you want to reuse (make a duplicate of) a network, you can use the name on a line with three node numbers (input, output, and reference ground). This is similar to named components but reuses the entire network. Our example did not reuse the RESONATOR network.

For information on plotting simulation results, see Outputs.

Substrates

To use substrates in a Netlist, use a SUB statement:

SUB substrateName

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This statement applies to all elements below it. substrateName refers to a substrate in the Workspace Window tree. See Substrates in this manual for more information on entering substrates.

Units In GENESYS

The units used in GENESYS are:

y Resistance: ohms

y Inductance: nanohenries

y Capacitance: picofarads

y 1/Resistance (G): Siemens (mhos)

y Group Delay: Nanoseconds

y Frequency: Megahertz

y Electrical Length: Degrees at the specified frequency

y Physical Length: Specified in substrate

Seeing Text Equivalents for Schematics

Most of the examples shipped with GENESYS 7 include schematic designs, not text netlists. However, you can very easily see the netlist for any of the included example schematics: right-click on the schematic node and select "Place Netlist in Notes". For instance, the text for the AMP schematic in "Balanced Amp.WSP" is:

TERM(50,50) TWO 1 2 3 FILENAME=AT41586.825 'Q1 SUB Default MLI 5 2 W=40 L=200 '!1 MCR 7 1 8 9 WT=W6 WC=W2 '!2 MVH 3 0 R=20 T=1 '!3 MVH 3 0 R=20 T=1 '!4 CAP 14 5 C=27 'C1 RES 8 14 R=680 'R1 MLI 2 15 W=W3 L=L3 '!7 MTE 15 16 17 WT=W3 WS=W4 '!8 MLI 17 18 W=W4 L=L4 '!9 CAP 16 19 C=27 '!10 MEN 18 0 W=W4 '!11


54

MLI 20 9 W=W2 L=L2 '!12 CAP 21 7 C=27 '!13 MEN 20 0 W=W2 '!14 DEF2P 21 19 AMP

Chapter 8: Designs: Layouts

Basics

Overview

NOTE: If you have not purchased =LAYOUT=, you may still use it in demo mode, but you cannot save your files. If you would like to purchase =LAYOUT=, please contact Eagleware for an authorization code.

=LAYOUT= is used for:

1. Creating a board description for an EMPOWER run.

2. Creating a board description for milling or etching a layout.

=LAYOUT= can be used with or without a starting design:

y If the layout will have lumped elements, a layout is usually created from a schematic.

y If no SuperStar simulation is to be performed, or if the layout contains some element which is not supported by SuperStar, the layout can be entered from scratch.

Creat ing A New Layout

There are 2 ways to create a layout:


1. Right-click on the Workspace Window "Designs/Models" node as shown in the figure below.

2. Click "Add Layout".

3. Name the new layout.

Designs: Layouts

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3. Select "Add Layout".

4. Name the new layout.

When you have created the layout, you should place objects on the layout using the toolbar.

To edit an existing layout:


1. Double-click the desired schematic under the "Designs/Models" node.


1. Double-click the desired layout in the list

or

2. Select the desired layout and click the "Open" button.

Note: For more information on how to use the Design Manager dialog, see the Reference manual.

If a layout refers to a schematic, then footprints, nodes, and rubber band lines will already be on the layout. The layout is ready to be completed. To complete the layout (details on each step are given later in the manual):

1. Change the footprint used for specific components. For example, change the footprint used by a specific capacitor to a larger or smaller footprint. Select a

Basics

57

component and click on the Change Footprint button ( ) on the toolbar.

2. Move and rotate footprints to the desired positions.

3. Place lines and arcs as required to connect footprints and resolve the rubber band lines

4. Place any other objects required, such as text, connectors, non-schematic footprints, and ground planes.

5. Output the finished layout to a printer, plotter, or file.

Lines, Rectangles and Arcs

Lines and arcs are typically used to make electrical connections. In layouts strictly for EMPOWER you should generally turn off the round ends for these lines and arcs. For most other purposes, you should use rounded-ends, as they will make better connections. Also, in layouts for EMPOWER, you may find it easier to use rectangle objects for most purposes.

To draw a straight line:

1. Select the Line button ( ) on the toolbar.

2. Change any settings on the toolbar.

3. Click and hold the left mouse button on the starting point of the line.

4. Drag the mouse to the ending point of the line and release the mouse button.

To draw another straight line immediately, simply press the space bar as a short cut for selecting the Line button on the tool bar. (If "Multi-Place Parts" is selected in the General tab of the Properties dialog, the Line button will remain selected; press Escape or select the Arrow button to deselect the Line button.)

To draw two connected orthogonal (90º) lines:

1. Follow the instructions above for connecting two nodes using a straight line. You should draw a diagonal line between the points to be connected. Press the letter O on the keyboard to convert the line to two orthogonal segments. (The status bar shows the available option keys.)

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2. Press the letter F on the keyboard to flip the orthogonal direction if necessary.

To draw a rectangle:

1. Select the Rectangle button ( ) on the toolbar.


3. Click and hold the left mouse button on the upper-left corner of the rectangle.

4. Drag the mouse to the lower-right corner and release the mouse button.

To draw an arc:

1. Select the Arc button ( ) on the toolbar.


3. Click and hold the left mouse button on the starting point of the Arc.

4. Drag the mouse to the ending point of the arc and release the mouse button. You should see a thin line between the start point and the mouse position as you are dragging the mouse.

5. Move the mouse to define the curvature of the arc. Click the left mouse button once to finish construction of the arc.

Using the toolbar, you can set round or square ends, width, and layer information for lines and arcs. Lines can also be made orthogonal (90 degree) using the toolbar or the line properties dialog box.

Selecting Objects

Objects in layout can be manipulated much like objects in any modern drafting or drawing program. Features like click and drag, handles, object selection, grouping, and screen panning have been included. Pay particular attention to the toolbar when selecting objects, as the possible actions listed there change whenever new objects are selected.

Generally, objects must be selected before they can be manipulated. Objects change color when selected.

To select a single object:

Basics

59

1. Be sure that the Arrow button ( ) on the tool bar is highlighted. This button indicates that no object is currently being constructed.

2. Click on the object to select with the left mouse button.

To select multiple objects by drawing a rectangle around them:

1. Be sure that the Arrow button on the tool bar is highlighted.

2. Click and hold the left mouse button in an open space on the layout.

3. Drag the mouse until a box is drawn which completely surrounds the items to be selected. The screen will pan if you reach the edge of the layout.


To individually select multiple objects:


2. Hold Shift down while clicking on a new object to select (or deselect) individual objects. Other selected objects will remain selected.

To select all objects:

1. Choose Select All from the Edit menu.

To select an object which is hidden behind other objects:


2. Click on the object to select with the left mouse button. (If you cannot see the object because its layer is hidden, you should click where the object would be if you could see it.)

3. If several objects overlap, continue clicking in the same spot until the desired object is selected. Layout will cycle through the overlapped objects with each click. Do not click too fast (double-click), or an object property dialog box may be displayed.

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Deleting Objects

Note: This method of deleting objects does not put the objects into the cut/paste buffer. For information on cutting and pasting, see that section later in the section.

To delete layout objects:

1. Select the object or objects which you want to delete.

2. Press the Delete key, or select Delete from the Edit menu to delete the objects. If you see a message which says "This object cannot be deleted since it has associated schematic objects", then you must use the steps given below.

Objects which have associated schematic elements cannot be directly deleted. Instead, you must either delete the element from the schematic, remove the schematic from the layout, or set the schematic object to not include a layout object.

To remove a schematic from the layout:

1. Select Properties from the Layout Menu.

2. In the General tab, deselect the schematic to remove it from the layout.

3. Press OK. All parts and rubber bands from the schematic will be removed.

To remove a layout object which has an associated schematic element:

1. Open the schematic.

2. Select the schematic element which corresponds to the layout element you wish to delete.

3. Double-click on the element, or select Parameters from the Edit Menu to bring up the element’s dialog box.

4. Press the Layout button in the dialog box.

5. Select either "Replace Part With Open" or "Replace Part With Short" as desired.

6. Select OK to close the Layout Options box.

7. Select OK to close the element’s dialog box.

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Moving Objects

Objects often must be moved to complete the layout. These objects can be moved using either the mouse or the keyboard.

To move objects with the mouse:

1. Select the objects to move as described in Selecting Objects.

2. Click and hold the left mouse button on the objects. Do not click on a handle.

3. Drag the mouse until the outlined image is in the desired location. The image will snap to the grid. If you drag the mouse off the edge of the screen, the screen will pan automatically.


To move objects with the keyboard:


2. Press the arrow keys on the keyboard to move the selected objects. Each press of an arrow moves the objects by the grid spacing entered in the General tab of the Properties dialog box.

Note: If you use the arrows on the number pad, be sure that Num Lock is turned off.

On rare occasions, you may want to move objects to a point not on the grid. Be aware that when doing so, it is easy to break electrical connections, so only use the following steps when absolutely necessary.

To move objects without snapping to the grid or to nodes:

y Follow the instructions above for moving objects with the mouse, but, during step 3, hold the Control key down while dragging the mouse.

Using Object Handles

In =LAYOUT=, objects can be modified in various ways using object handles. Object handles are small squares which appear when an object is selected. Object handles can only be manipulated with the mouse.

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To use an object handle:


2. Click and hold the left mouse button on an object handle.

3. Drag the mouse to manipulate the object. An outline image will update as changes are made. If you drag the mouse off the edge of the screen, the screen will pan automatically.


On rare occasions, you may want to manipulate object handles without snapping to the grid, nodes, or a specific angle. Be aware that when doing so, it is easy to break electrical connections or to rotate parts to nonstandard angles, so only use the following steps when necessary.

To use an object handle without snapping to grid, nodes, or angles:

y Follow the instructions above for using an object handle, but, during step 3, hold the Shift key down while dragging the mouse.

Using Object Property Dialogs

Object property dialogs are used to adjust any properties of an object. These dialogs are especially useful when exact coordinates for objects must be entered. They are also shown automatically during construction of ports, text, viaholes, and pads. See the Reference manual for details on specific object property dialog boxes.

To change an object using the object property dialog box:

1. Double-click on the object.

2. Make any desired changes in the dialog box.

3. Select the OK button to close the dialog box.

To change an object using the object property dialog box without using double clicks:

1. Select an individual object as described on in Selecting Objects.

2. Select Parameters from the Edit menu (or press Enter).

3. Make any desired changes in the dialog.

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4. Select the OK button to close the dialog.

Cutting And Pasting

Layout objects can be cut, copied, and pasted. This allows for easy duplication of objects. =LAYOUT= remembers the last cut or copied objects until GENESYS is exited. Only one cut/paste buffer is used for both the standard =LAYOUT= editor and the footprint editor, allowing objects to be cut and pasted between them.

Note: New with Version 7, the layout can be pasted to other applications.

CAUTION: The contents of the cut/paste buffer are lost when GENESYS is exited.

To cut objects, removing them from the layout:

1. Select the objects to be cut as described in Selecting Objects.

2. Select Cut from the Edit menu.

Objects associated with schematic elements cannot be cut. If a message appears stating that an object cannot be deleted since it has associated schematic elements, then you should use copy instead.

To copy objects to the buffer, leaving them on the layout:

1. Select the objects to be cut as described in Selecting Objects.

2. Select Copy from the Edit menu.

Once cut or copied to the buffer, duplicates of objects can be pasted back to the layout. As many duplicates can be pasted as is desired. Duplicates are always pasted to the same place as the original objects and are then be moved to the desired location.

To paste duplicates of the last objects cut or copied:

1. Select Paste from the Edit menu.

2. Move the objects as desired using the mouse or keyboard.

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Note: Objects pasted will not be associated with schematic elements, even if the original objects had associated schematic elements.

Grouping Objects

Objects may be combined into groups. (The only exception is port objects which may not be put into groups.) This keeps the objects connected together as they are moved or rotated. Groups may be nested, so that one group contains other groups and objects. When objects are grouped, there is no change to the final output generated by =LAYOUT=; groups are simply a editing convenience.

To group two or more objects together:

1. Select the objects as described in Selecting Objects.

2. Click on the Group button ( ) on the toolbar (or press the letter G on the keyboard).

To ungroup previously grouped objects:

1. Select the group as described in Selecting Objects.

2. Click on the Ungroup button ( ) on the toolbar (or press the letter U on the keyboard).

Automatically Connecting Layout Objects

New in GENESYS 7, =LAYOUT= can automatically snap parts together. This is most useful for Microstrip/Stripline circuits which have parts automatically created from a schematic (such as files from =M/FILTER=). For example, in two easy steps you can turn this layout:

into this layout:

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65

To automatically connect objects:

1. Select the objects to be connected as described in Selecting Objects.

2. Choose Connect Selected Parts from the Layout menu.

Default Text Font

Most text which is placed on the layout is associated with a footprint, and the font and size cannot be controlled individually. Rather, the default font and size can be changed, which changes the text for all such objects simultaneously.

To change the default font and size:

1. Select Properties from the Layout menu.

2. Select the Fonts tab.

3. Select the new default font from the list.

4. Enter the new default size.

5. Press OK.

This process adjusts the font and size of all text objects which were marked (in their property dialog boxes) to use the default font or the default size. This includes all text in footprints from libraries supplied with =LAYOUT=.

Fonts And Text Objects

Text objects in layout can use a variety of different included fonts, or can use a TrueType font provided by the user. =LAYOUT= includes the following fonts (Complexity directly relates to Gerber file size):

DEFAULT.EWF - a thin font. This font is appropriate for use on most boards. Complexity (1-10): 4

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EURO.EWF - a thin font which is somewhat more boxy than DEFAULT.EWF. Complexity: 4

GOTH.EWF - A very artistic gothic font. Complexity: 10

LCOM.EWF - A font resembling Times Roman. This font is especially useful for placing a large company name on a layout. Complexity: 6

LITT.EWF - A very simple thin font. This is the simplest provided font. Complexity: 2

SANS.EWF - A sans serif font of medium stroke thickness. Complexity: 7

SCRI.EWF - A thin ornamented font designed to resemble handwriting. Complexity: 5

TRIP.EWF - A bold font resembling Times Roman Bold. Complexity: 9

TSCR.EWF - A bold italic font resembling Times Roman Bold Italic. Complexity: 9

The provided fonts are all in Eagleware Font (.EWF) format, a proprietary font format. They are located in the FONT subdirectory of the main Eagleware directory (C:\EAGLE\FONT, for example). If additional fonts are needed, TrueType fonts (.TTF) may be copied into this directory, with the following caveats:

1. There are many different TrueType font formats available, and not all are guaranteed to work in =LAYOUT=.

2. When text using a TrueType font is converted to Gerber format, each letter of the text is converted into a filled polygon. Extremely large Gerber files will result if TrueType fonts are used extensively. TrueType fonts are best used for highlights and end-user instructions, such as a company name and logo or jumper settings. In contrast, the size of text in a Gerber file using an .EWF font is roughly proportional to the complexity of the .EWF font.

To place text on the layout:

1. Select the Text button ( ) on the toolbar.

2. Click the left mouse button on the layout to place text. This brings up the text property dialog box.

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3. Type the text to place into the "Text" field.

4. Change any other settings, such as the font, layer, size, and justification,

5. Press OK.

To edit the contents of an existing text object:

1. Select the text object as described in Selecting Objects.

2. Select Parameters from the Edit menu to bring up the text property dialog box.

3. Edit the text shown in the Text entry field.

4. Press OK.

To change the font used by an existing text object:



3. Choose a font from the Font combo box.

4. Press OK.

To change size of an existing text object:



3. If the "Use Default Size" box is checked, deselect it by clicking on it with the left mouse button.

4. Type the desired text size into the Text Size box. The size is given in the units specified in the General tab of the Properties window.

5. Press OK.

Pads

There are three types of pads available: round, square/rectangular, and wagon wheel. These three pad types are shown in the figure below. Wagon wheel pads are often used for thermal relief when connecting to a ground plane, making soldering easier.

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To place a pad on the layout:

1. Select the Pad button ( ) on the tool bar.


3. Click the left mouse button on the layout to place the pad. This will bring up the pad property dialog box.

4. Fill in the desired options and press OK.

The solder mask layer for a pad is automatically generated. The shape of the mask which is placed is shown in in the figure above. If the pad’s layer is marked as mirrored in the layer table, then the mask goes on the next mask layer below the pad’s layer. Otherwise, the mask goes on the next mask layer above the pad’s layer.

If a mask is not needed for a particular pad, then it can be turned off for that pad.

To disable mask generation for a particular pad:

1. Bring up the pad’s property dialog box. (Double-click on the pad.)

2. Select the check box labeled "Don’t Create Mask."

3. Press OK.

When pouring a ground plane polygon, the keep away applies to pads as well as to other objects. If a pad is marked as "User Ground," then the ground plane will touch the pad (and any lines and arcs connected to it) instead of avoiding it.

To mark a pad as a grounded object:

1. Bring up the pad’s property dialog box. (Double-click on the pad.)

2. Select the check box labeled "User Ground."

3. Press OK.

Viaholes

Viaholes are drilled, plated through-holes used to connect traces on different layers. Viaholes may be blind or buried, meaning

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that they are not drilled through all layers. Viaholes automatically place a pad (round, square, or wagon wheel) on each metal layer between the start (top) and end (bottom) of the viahole (including pads the start and end layers). The drill hole is always in the center of the pads. Electrically, viaholes connect every layer between the start and end layers.

To place a viahole on the layout:

1. Select the Viahole button ( ) on the tool bar.


3. Click the left mouse button on the layout to place the viahole. This will bring up the viahole property dialog box.


Viaholes automatically generate solder mask for the topmost and bottommost pads. The shape of the mask which is placed is identical to shapes placed for pads and is shown in the figure below. If a mask is not needed for a particular viahole, then it can be turned off for that viahole.

To disable mask generation for a particular viahole:

1. Bring up the viahole’s property dialog box. (Double-click on the viahole.)

2. Select the check box labeled "Don’t Create Mask."

3. Press OK.

When pouring a ground plane polygon, the keep away applies to viahole pads as well as to other objects. If a viahole is marked as "User Ground," then the ground plane will touch the viahole’s pads (and any lines and arcs connected to them) instead of avoiding them.

To mark a viahole as a grounded object:

1. Bring up the viahole’s property dialog box. (Double-click on the viahole.)

2. Select the check box labeled "User Ground."

3. Press OK.

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Blind or buried viaholes are holes which are not drilled through the entire board. These viaholes can be useful in multilayer boards to connect some layers while leaving other layers unaffected. This utility comes at an expense, as production of boards with blind and buried viaholes is often more expensive.

To place a blind or buried viahole on the layout

1. Select the Viahole button on the tool bar.


3. Click the left mouse button on the layout to place the viahole. This will bring up the viahole property dialog box.

4. Deselect the check box labeled "Use Default Layers." This will allow the start and end layers to be changed.

5. Select the desired start and end layers from the start and end layer combo boxes.


Components & Associations

Components

Component Objects are placed on the layout to represent lumped elements, such as resistors, transistors, and integrated circuits. They can also be used if a complex pattern needs to be repeated on many layouts, such as connectors. Place a component object using the component button ( ) on the =LAYOUT= toolbar.

All components are based on a footprint in a footprint library. A footprint is a pattern of metal, silk, and other layers which generally corresponds to a physical part, such as SOT23 or 0603 packages. Footprints can be created or edited using the footprint editor. If a footprint library is changed, then all components (in all layouts) using that footprint will be updated.

If a layout is based on one or more designs, then components (and rubber bands) will be placed automatically corresponding to the design topologies. The General tab in the Layout Properties Dialog controls which designs to include in the layout. The Association Table is used to determine which footprint to use for each type of element. If any components are added, modified, or


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deleted in the designs, then the layout components (and rubber bands) are automatically added, modified, or deleted.

Nodes and Rubber Band Lines

Nodes (shown as green dots) are shown in =LAYOUT= where electrical connections can be made. Any objects placed or handles moved will automatically snap to a nearby node to ensure a true connection. These nodes allow consistent electrical connections to be made even when parts do not line up on a grid. (If at any point you do not want to snap to the grid or to a node, hold the Shift key down while moving or constructing an object.)

Rubber band lines (shown as thin white lines) are shown in =LAYOUT= where electrical connections must be made. These connections are determined from the designs. The rubber band lines are updated whenever the designs are changed. Rubber band lines disappear automatically as connections are made.

Rubber band lines show only one possible set of connections. For example, Figure (a) below shows three elements that should be connected. The most obvious connection method is shown in Figure (b). However, the rubber band lines do not need to be followed exactly, and the connections shown in Figure (c) also resolve the rubber bands since they electrically connect the three nodes.

Note: No other objects besides lines, arcs, or viaholes can be used to resolve rubber bands. For instance, if a polygon is placed between two nodes, those two nodes are not considered to be connected, even if the polygon appears to connect the two nodes.

The automatic resolution, or removal, of rubber band lines is intelligent. Any combination of lines, arcs, and viaholes can be used to make connections; =LAYOUT= will resolve the rubber bands properly no matter how complex the interconnections are.

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Note: One cause of rubber band lines not disappearing is failure to actually connect nodes together. If rubber bands do not disappear, zoom in and examine the nodes to make sure that the connections were made properly.

Tip: A common mistake is to use a "fine" grid. This allows components to "look" connected, but they may actually have a small gap between. On large layouts this sort of problem can be hard to find, so by keeping the grid spacing coarse you ensure that actual connections take place.

See the earlier section "Lines, Rectangles and Arcs" for information on drawing lines and arcs.

Association Tables

Association tables are used by =LAYOUT= to determine which footprint to initially use for each type of design element. This association table is used any time the layout is updated if there are new elements on the design. It is only used once for any given element. This footprint can be later changed from within =LAYOUT= to override the association table. The association table is also used whenever a new layout is created which includes designs.

The following steps may clarify the use of the association table:

1. A new schematic is created containing a capacitor, C1.

2. A new layout is created. In the association table, the entry for CAP shows the library "SM782.LIB" and the footprint shows the name "CC1005 [0402] Chip Capacitor." This footprint is automatically placed on the layout for the capacitor.

3. If the association table is changed later, it has no effect on the capacitor that was already placed.

4. If the footprint for the existing capacitor is changed (to "CC2012 [0805] Chip Capacitor," for example), it will not automatically change back to the association table entry.

5. Even if the schematic is modified, the capacitor does not automatically move or change back to the association table entry.


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6. If the schematic element is deleted, then the corresponding part in the layout will be deleted.

7. If an association table contains a multi-device footprint (such as a quad op-amp footprint), then all devices in each component will be used before beginning a new one. For example, if a schematic contains seven op-amps, and the OPA entry in the association table contains a quad op-amp footprint, then two components will be placed, the first using all four devices, and the second using three of its four devices. Use "Switch/Move Parts" from the Edit Menu to change which OPA element uses which device in which package.

Whenever a file containing a layout which depends on a schematic is loaded, the date of the schematic file is checked against the date of its association table. If the association table is newer than the schematic file, then a message is given. This message is useful to help ensure that outdated footprints are not accidentally used in a layout.

Overriding Association Defaults

As described in item four in Association Tables, once a component has been automatically generated for a schematic element, its footprint can be changed. The component will continue to use the new footprint even if the schematic is modified.

To change a component’s footprint:

1. Select a component as described in Selecting Objects.

2. Click on the Change Footprint button ( ) on the toolbar.

3. Select a footprint from the library selector.

Association Table Maintenance

The association table is found in the Associations tab of the Properties/Create New Layout dialog box. It is generally modified only when a new layout is created. It can also be accessed by selecting Properties from the Layout menu, but it will not be used again until a new component is added or a new layout is started.

To modify an entry in the association table:


2. Select the Associations tab.

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3. Scroll the table to the desired entry.

4. Click the "Change" button.

5. Select a footprint from the library window and click OK.

The association table will automatically be saved using the current name when the window is closed, or can be saved immediately to a new name.

To save the association table to a new file:



3. Click the "Save As" button.

4. Select a filename and press OK.

Note: The .TBL file must be saved into the \EAGLE\LIB subdirectory. Tables saved into other directories cannot be used.

To load a previously saved association table:



3. Click the "Load Table" button.

4. If the current table had been modified, a message will ask if you want to save the current table. Click on a button to continue.

5. Select a filename and press OK.

Automatic Transmission Line Generation

In typical digitally oriented PCB layout or CAD programs, transmission lines and their junctions (discontinuities) must be manually generated. This is often tedious, time consuming, and error prone.

In contrast, =LAYOUT= automatically generates footprints for microstrip and stripline elements entered into SCHEMAX. The dimensions of these footprints are automatically determined from the schematic elements and substrate parameters, ensuring that the board is laid out exactly as it was simulated. The following element types are handled automatically by =LAYOUT= (and, correspondingly, are not listed in the association table):


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Microstrip and stripline bends (MBN, SBN) - a square or chamfered (triangular) polygon for the corner section.

Microstrip and stripline single lines and coupled lines (MCN, MCP, MLI, MTAPER, SLI, SCN, SCP) - lines and spacings are generated

Microstrip cross and tee, and stripline tee (MCR, MTE, STE) - a square or rectangular polygon for the area where three or four lines come together

Microstrip curved line (MCURVE) - a curved line is generated.

Microstrip inductors & capacitors (MIDCAP, MRIND, MSPIND) - complex footprints representing these parts are generated.

Microstrip and stripline open end effects (MEN, SEN) - have no size and are removed from the layout

Microstrip and stripline gaps (MGA, SGA) - two small metal guide pieces separated by the gap width

Microstrip radial stub (MRS) - generates a pie shaped piece.

Microstrip and stripline steps (MST, SSP) - removed for symmetrical microstrip and stripline steps. For asymmetrical microstrip, two guide pieces plus nodes are generated.

Microstrip viaholes (MVH) - generates a viahole with its pads

Note: Be sure that the units given in the substrate are correct, as these are the units used for generating the microwave footprints. The units specified in the General tab of the Properties box are not used for this purpose.

When a layout containing these elements is created, footprints for these elements are generated automatically and are connected by rubber bands initially just like any other elements. The main difference is that instead of connecting these elements with lines, they are normally mirrored, moved and rotated until their nodes join, eliminating the rubber band lines. These parts can be joined manually or automatically.

To automatically join multiple microwave footprints:

y Follow the procedure described previously in "Automatically Connecting Layout Objects".

To manually join together two microwave footprints:

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1. Select the first object as described on in Selecting Objects.

2. If the first object must be mirrored, press the Mirror button ( ) on the toolbar.

3. Use the object handles to rotate and move the object as necessary. For unusual positioning or rotation angles, use the component property dialog box (double-click on the object or select Details from the Edit menu).

4. Select the second object as described in Selecting Objects.

5. If the second object must be mirrored, press the Mirror button on the toolbar.

6. Use the object handles to rotate the object as necessary. For an unusual rotation angle, use the object property dialog box.

7. There will be a rubber band connecting a node on the first object (node A) with a node on the second object (node B). Click and hold the left mouse button on node B.

8. Drag the mouse to node A. The two objects will snap together, eliminating the rubber band.

Statistics Window

To view your progress resolving rubber bands, you can check the statistics window (sometimes referred to as a scorecard). This window tells how many rubber bands there were initially and how many rubber bands have been successfully resolved.

To view the statistics window:

y Select Statistics from the Layout menu.

Converting A Component To A Group

When a component is placed on the layout, only simple changes can be made to it:

y The component can be moved, rotated, or moved to a new layer.

y Text can be changed or removed from the object property dialog box.


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y Text can be moved using object handles.

y The silk screen can be hidden using the component property dialog box.

If other changes to the object are needed, the footprint editor is generally used. However, if the change is unique, like removing unused pins from an edge connector, then the change can be made from within =LAYOUT= by first converting the component to a group.

To convert a component to a group:

1. Place the component using the Component button ( ) on the toolbar, if the component is not already on the layout.

2. Select the component as described on page .

3. Press the "To Group" button ( ) shown on the toolbar.

The object has now been converted to a group. It may be ungrouped (see above) and edited.

Note: If a message box appears stating "This object cannot be changed to a group since it has associated schematic elements" then follow the instructions in Deleting Objects above to remove the link.

Multi-Device Footprints

In =LAYOUT=, multi-device footprints such as resistor packs or quad op-amp ICs are supported. The creation of these footprints will be described in the Footprint Editor section; the current discussion will only cover their use in a layout.

Several previously discussed concepts will be useful:

To move two or more individual parts with associated schematic elements into a multi-part footprint:

1. Select the component to be placed in device A, as described in Selecting Objects.

2. Click on the Change Footprint button ( ) on the toolbar.

3. Select the desired multi-device footprint from the library window.

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4. Choose Switch/Move Parts from the Layout Menu. For the next several steps, help will appear on screen in the status bar.

5. Select the next component to place into the multi-part package.

6. Select the component with the multi-device footprint to place the second component into.

7. A message will appear stating that the original component no longer is associated with any schematic elements and asking if the original part should be deleted. Normally, you will press the "Yes" button.

8. Repeat steps five through seven for any remaining individual parts to place into the multi-part footprint.

Sometimes, you may want to switch existing component associations. For example, if there is are two quad op-amp packages on the layout, each with four associated schematic elements, you may want to change which device is associated with which element.

To switch or move schematic associations between two component devices:

1. Choose Switch/Move Parts from the Layout Menu. For the next several steps, help will appear on screen in the status bar.

2. Select the first component’s device to switch. This component must have an associated schematic element.

3. Select the multi-device footprint to switch with or move into.

4. If a message appears stating that the original footprint no longer is associated with any schematic elements and asking if the original part should be deleted, you will normally press the "Yes" button.

See Association Table Maintenance to modify an association table to use multi-device footprints.

See Overriding Association Defaults to change the footprint of an existing part.

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Power And Ground Connections

Some multi-part footprints contain extra ports that are not used by any device (marked with "*", or None, in the footprint editor). These ports are most commonly used for power and ground connections and must be connected manually; no rubber bands will appear to ensure their connection.

Caution: Be sure to remember to make any necessary power and ground connections to footprints. Again, there will not be any rubber bands on these pins to help you remember.

Layers

Layer Table

=LAYOUT= can deal with almost any board configuration, from a simple one-layer board to a complex sixteen or more layer board. Mixed media, such as combining microstrip with stripline, can be easily accommodated. =LAYOUT= recognizes six distinct layer types. They are:

y Metal - all conductive traces go on a metal layer. Only traces on metal layers are used to automatically resolve rubber bands.

y Silk - silk screen is used for labels on the final board. It is generally white or yellow on the production board. Silk screen objects should not overlap with solder mask objects.

y Substrate - can be used to designate cuts in the circuit board. If automatic cutting is to be used, then only straight or orthogonal rounded-end lines should be used on this layer type. The center of these lines represents the saw path for cutting.

y Assembly - an intermediate layer that indicates exact placement of components. It is only used as an aid in the production process and is not seen on the final board.

y Mask (Solder Mask) - a negative layer: objects on this layer indicate an absence of solder mask. This layer is automatically generated from pads and viaholes and generally does not require user intervention.

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y Paste (Solder Paste) - objects on this layer indicate places where solder paste is to be used. If a solder paste layer is required, it must be manually generated.

There can be up to 128 different layers used, and each type can be used as often as desired. Some possible layer setups are:

y For a simple, single-layer board or prototype with a solid ground plane (no traces or cutouts on the ground plane) (SIMPLE.LYR):

1: Silk 2: Metal

y For a typical single-layer production board (SINGLE.LYR):

1: Top Assembly 2: Top Silk 3: Top Mask 4: Top Metal 5: Substrate 6: Bottom Metal (Mirrored) 7: Bottom Mask (Mirrored) 8: Bottom Silk (Mirrored) 9: Bottom Assembly (Mirrored)

y For a four-layer production board (FOUR.LYR):

1: Top Assembly 2: Top Silk 3: Top Mask 4: Top Metal 5: Substrate 1 6: Metal 2 7: Substrate 2 8: Metal 3 9: Substrate 3 10: Metal 4 11: Substrate 4 12: Bottom Metal (Mirrored) 13: Bottom Mask (Mirrored) 14: Bottom Silk (Mirrored) 15: Bottom Assembly (Mirrored)

Layer information is entered into the General Layer Tab of the Properties dialog box. See the Reference manual for more information on this dialog.

Hiding Layers

Often it is desirable to turn off the display of certain layers. For example, if an assembly layer is not being modified, it can be hidden:

To hide or unhide a layer:


2. Click on the General Layer Tab.

3. Scroll down to the desired layer.

4. Click on the check box in the column labeled "hide" to toggle the check box.

5. Click on the OK button to return to the layout.

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Mirrored Layers

Layers on the back side of a board should be mirrored. For example, when viewing from the top of the board, the lettering and component footprints should be reversed.

To mark a layer as mirrored:


2. Click on the General Layer Tab.

3. Scroll down to the desired layer.

4. Click on the check box in the column labeled "Mirror" to toggle the check box.

5. Click on the OK button to return to the layout.

When a layer is marked as mirrored, all new and existing text and components placed on that layer will be mirrored.

.LYR Files

Layer setups can be saved into files for later use in other boards. For example, the sample layer settings given above are included in .LYR (layer) files in your Eagleware directories.

To save layer settings into an .LYR file:


Click on the General Layer Tab.

2. Press the "Save to Layer File" button.

3. Choose a filename for the layer file and press OK.

To load layer settings from an .LYR file:


Click on the General Layer Tab.

2. Press the "Load from Layer File" button.

3. Choose the layer file to load and press OK.

Unlike footprint library files, .LYR files do not remain associated with a particular layout. If layer settings are saved to an .LYR file, and the settings are later changed in the current layout, then the .LYR file does not update automatically. Conversely, if the .LYR file is later changed, no layouts are changed unless the .LYR file is explicitly loaded.

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Polygons, Pours, and Ground Planes

Polygons

Polygons are filled areas on the layout. Polygons can be used on any layer, can be any shape, and can even have cutouts (holes). Some typical polygons are shown in the figure below. Polygons are often used for landing pads with unusual shapes. Polygons should only be used when necessary if a Gerber file will be created from the layout, since the use of polygons can drastically increase the disk size of a Gerber file.

To construct a polygon:

1. Select the Polygon button ( ) on the tool bar.


3. Click the left mouse button at the first vertex (corner) of the polygon.

4. Click the left mouse button at the next vertex.

5. Continue clicking at all vertices. Double click at the last vertex (or click again on the first vertex) to complete construction of the polygon.

To add a cutout (hole) to a polygon:

1. Select the polygon as described in Selecting Objects.

2. Select the Cutout button ( ) on the toolbar.

3. Click the left mouse button at the first vertex (corner) of the cutout. (All vertices and lines of the cutout should be within the original polygon and should not overlap any other cutouts in that polygon.)

4. Click the left mouse button at the next vertex.

5. Continue clicking at all vertices. Double click at the last vertex (or click again on the first vertex) to complete the cutout.

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Poured Polygons

A polygon can be poured, which causes it to keep away from other objects by a specified amount. The figure below shows a polygon which has been poured around two pads and a line. The keep away distance is the distance that the pour stays from the line and pads and is the width of the white space in the figure. Pours are often used for coplanar ground plane. Pours should only be used when necessary if a Gerber file will be created from the layout, since the use of pours can drastically increase the disk size of a Gerber file.

To pour (or re-pour) an existing polygon:

1. Select the polygon as described in Selecting Objects.

2. Select the Pour ( ) button on the toolbar. This will bring up the pour property dialog box.

3. Type the desired keep away distance. The units for keep away and resolution are the current units as specified in the General tab of the Properties dialog box.

4. Type the desired resolution. All pours consist of only straight line pieces. This value indicates how precisely to approximate curves with straight lines. A lower number for resolution means better quality. This number should generally be about one tenth the value of the keep away. For example, if a 20 mil keep away is used, a 2 mil resolution is generally appropriate.

5. Select the desired number of segments. This divides the pour into multiple pieces. It does not affect the quality of the final output, but it may be necessary to increase the number to simplify complex pours. Normally enter 1 for # Segments. If the pour is not complete, increase this number to 2, 3, or more as necessary.

6. Press OK to begin pouring the polygon. A box appears showing the status of the pour.

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Ground Plane Pours

Pours are especially useful for constructing ground planes. Ground plane pours have the intelligence to touch objects which are marked as "User Ground" and to keep away from other objects. Lines and arcs which touch grounded viaholes and pads are also considered to be grounded; this intelligence is similar to the intelligence used to resolve rubber bands.

To pour an existing polygon as a ground plane:

y Follow the instructions in Poured Polygons, but before pressing OK in step six, toggle the Ground Plane check box.

Chapter 9: Designs: Link to Spice File

Overview

One of the easiest ways to get nonlinear device models into GENESYS for use with HARBEC is to use a link to a manufacturer supplied SPICE file. SPICE files have the following advantages over other methods of using nonlinear device data:

y They are often supplied by manufacturers.

y Entering device data manually is tedious and error-prone.

y SPICE files often contain very complete macromodel device characterizations.

They also have a few disadvantages:

y Model parameters cannot be tuned directly in GENESYS.

y SPICE data provided by manufacturers are often intended for low-frequency use and may not adequately characterize high-frequency behavior. (This is generally not a problem for devices intended for use at high frequencies.

To create a link to a SPICE file:

1. If workspaces using the spice link will be shared with co-workers, then we recommend placing the spice file either on a network drive which has the same letter for all co-workers, or, better, into your GENESYS\model directory or a subdirectory there.

2. Right-Click on Designs in the Workspace Tree and select Add Link to SPICE File.

3. If you want this link to be available automatically everytime you start genesys, you should answer Yes and then save your file into the model directory.

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4. Click the "..." button on the SPICE Link dialog box and choose your spice library from the browse box. Press OK.

5. Choose the desired model or subcircuit from the combo box.

6. Normally, the only other necessary change in this box is checking or unchecking "Reverse Nodes 1 & 2". This box tells GENESYS that the spice subcircuit uses the spice node-numbering convention (Input=2, Output=1). Normally, you will check this box if the data represents a transistor or amplifier.

7. Click OK.

8. Generally, you should allow GENESYS to rename your model to be the same name as the spice model to avoid confusion.

Note: GENESYS will not allow 2 models with the same name to be loaded. If you create a SPICE model with the same name as an existing part, GENESYS will give an error at startup. If this happens, simply load your workspace and rename the spice link.

To use a link to a SPICE file:

1. On a schematic, place a part with the symbol you want for the link. For example, if you are placing a Bipolar Transistor, place a bipolar symbol.

2. Double-click on the part.

3. From the Schematic Element Properties Dialog box, click the model button.

4. From the Choose Model dialog box, choose the file and model with the spice link. Click OK, and Click OK.

SPICE File Compatibility

GENESYS is compatible with Berkeley SPICE3. Where possible, GENESYS has also been made compatibile with PSpice. The following devices can be used in a SPICE link:

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B - Arbitrary Source. Note: SPICE 2 uses B for MESFET's. If you have a file using this convention, you must change the B prefix to Z and change the model name from MESFET to NMF or PMF

C – Capacitor

D - Nonlinear Diode

E,F,G,H - Controlled Sources

I - Current Source

J - Nonlinear JFET: Only JFET; JFET2 is not yet available.

K - Mutual Inductance

L – Inductor

M - Nonlinear MOSFET: As of GENESYS Version 7.5 release, only level 1 (MOS1) is available.

Q - Nonlinear BJT

R – Resistor

V - Voltage Source

X – Subcircuit

Z - Nonlinear MESFET Transistors. Model types NMF and PMF are available. You must add a level parameter to the model to indicate which type of MESFET model will be used: 1=Curtice Quadratic, 2=Statz, 3=TOM, 4=Original SPICE 3F5 MESFET, 5=TOM2, 6=Curtice Cubic. For parameter details see the corresponding element in the Reference chapter.

For example, a SPICE model for an XYZ143 device using a TOM N-Channel model in it might look like:

.model XYZ143 NMF (LEVEL=3 VTO=-2.5 CGS=1e-12)

If there are any compatibility errors in the SPICE file, the errors will appear in the GENESYS error window when a DC or HARBEC simulation is run which uses the link.

Chapter 10: Designs: Single Part Model

Overview

Selecting "Add Model (Single Part)" from the Designs/Models right-click menu displays the dialog box shown below. This box defines the underlying part that will be used as the model. This dialog is the same as the Choose Model dialog box in SCHEMAX.

The complete process to enter a single part model is:

1. Right click the Designs/Models icon in the workspace manager, and select "Add Model (Single Part)."

2. Name the part. The system asks if you want to store the file in the model directory. When stored in this directory, it is easy to reuse the part in other designs.

3. Choose a base model. The single part model can be based on any part. Typically this will be a nonlinear part such as a BJT model.

4. Enter the parameters for the part. The parameters that you enter will be used as the default for the part.

5. Use the part in a schematic. Enter a part that has a desired symbol. Change it to use your new Single Part model using the "Model?" button on the part dialog.

One advantage of the single part model is that default values can be easily overridden when used design. If you are used to Model statements in other simulators, single part models allow you to follow this paradigm while giving more flexibility.

Chapter 11: User Footprints

Overview

Four footprint libraries are included with =LAYOUT=. See Provided Footprint Libraries later in this manual for more details on these libraries.

1. A library based on the IPC SM 782 surface mount standard (SM782.LIB)

2. A leaded component library (LEADED.LIB) 3. A library of sample footprints (SAMPLE.LIB) 4. A small library of active RF devices (HPLIB.LIB).

=LAYOUT= also includes an editor for creation and editing of footprints and libraries. The footprint editor can be started using Footprint Editor/New Footprint from the Tools menu. The figure below shows a sample Footprint Editor window.

To create a footprint:

1. Select Footprint Editor/New Footprint from the Tools menu.

2. Place objects in the editor. Pads should be placed wherever solder connections will be made.

3. Place silk screen objects (e.g. designators, etc.). 4. Place ports. Ports must always be placed before a

footprint can be saved. 5. Save the footprint in a library file by selecting "Save

Footprint" from the Tools/Footprint Editor menu.

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Layers In The Footprint Editor

The following layers are available in the footprint editor: 1. Top Assembly 2. Top Silk 3. Top Paste 4. Top Mask 5. Top Metal 6. Sub Above 7. Metal 8. Sub Below 9. Bottom Metal 10. Bottom Mask 11. Bottom Paste 12. Bottom Silk 13. Bottom Assembly

For almost all components, pads should be placed on the "Metal" layer (not "Top Metal"), and all silk screen objects should be placed on "Top Silk" or "Bottom Silk".

Note: If you might ever use your footprint on the back side of a board, you must place your pads on the Metal layer (not Top Metal) so that =LAYOUT= will automatically mirror your pads and move the component to the back of the board.

Loading And Merging Footprints

To load an existing footprint: 1. Select Footprint Editor/Load Footprint from the Tools

menu. 2. Select the library file which contains the footprint from

the Select Library box. 3. Select the footprint from the "Available Footprints" box. 4. Choose the OK button to load the selected footprint.

To merge an existing footprint with the current footprint 1. Select Footprint Editor/Merge Footprint from the Tools

menu. 2. Select the library file which contains the footprint from

the Select Library box. 3. Select the footprint from the "Available Footprints" box. 4. Choose the OK button to merge the selected footprint.

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Creating And Saving Footprints

To create a new footprint: 1. Select Footprint Editor/New Footprint from the Tools

menu. If a footprint editor is already present, a new editor will be created.

To update an existing footprint:

Warning: The old footprint will be lost if this method is used to save. This will modify any layouts using the old footprint. We suggest using a new name in case the old footprint is needed later.

y Select Footprint Editor/Save Footprint from the Tools menu.

y Select the library which contains the old footprint from the Select Library box.

y Select the name of the footprint from the "Available Footprints" box.

y Select OK. To add a new footprint to an existing library

y Select Footprint Editor/Save Footprint from the Tools menu.

y Select the library to append the footprint to from the Select Library box.

y Select "<New Object>" from the "Available Footprints" box.

y Select OK. y When the "Choose Name For Component" box appears,

type a new name for the footprint and select OK. To create a new library and save the current footprint into it:

1. Choose "Save Footprint" from the Tools/Footprint Editor menu.

2. Choose "<New File>" from the Select Library box. "<New Object>" should be automatically selected in the "Available Footprints" box.

3. Select OK. 4. When the "Choose New Name For Library" box appears,

type a name for the new library file and choose Save. 5. When the "Choose Name For Component" box appears,

type a new name for the footprint and select OK.

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Renaming And Deleting Footprints

To rename a footprint: 1. Choose Footprint Editor/Modify Footprint Library from

the Tools menu. 2. Select the library which contains the footprint from the

"Select Library" box. 3. Select the footprint from the "Available Footprints" box. 4. Select "Rename Footprint". The "Rename" box appears

containing the current name of the footprint. 5. Type a new name for the footprint and choose OK.

To delete a footprint: 1. Choose Footprint Editor/Modify Footprint Library from

the Tools menu. 2. Select the library which contains the footprint from the

"Select Library" box. 3. Select the footprint to delete from the "Available

Footprints" box. 4. Select "Delete Footprint".

Placing Objects In The Footprint Editor

Objects in the footprint editor are placed exactly the same way that they are placed in the layout editor. The available objects are listed on the toolbar at the top of the editor window. They are as follows:

y Lines ( ) y Rectangle ( ) y Arcs ( ) y Polygons ( ) y Ports ( ) y Text ( ) y Viaholes ( ) y Pads ( )

To place an object, select the appropriate button from the toolbar. Then, click within the editor window to place the object at the desired location. Whenever an object is selected, the toolbar shows the available options for that object. Before an object is placed, any of these options can be changed.

Placing Pads In The Footprint Editor

Pads should be placed wherever solder connections will be

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made. Pads always have a node at the center, regardless of the pad shape. To place a pad on the footprint:

1. Select the Pad button ( ) on the toolbar. Change any settings on the toolbar.

2. Click the left mouse button on the footprint to place the pad. This will bring up the pad property dialog box.

3. Fill in the desired options and press OK. For more information about pads, see Pads in the previous chapter on Layouts.

Placing Ports In The Footprint Editor

Ports must be placed before a footprint can be saved to a library. They designate where layout parts will connect (e.g. lines, arcs, other footprints, etc.). For multiple component footprints such as a quad op-amp IC, ports are used to identify the different components. For example, port "A1" could be used for pin 1 of op-amp #1. Port D-3 could be pin 3 of op-amp #4. To place a port on the footprint:

1. Select the Port button ( ) on the toolbar. Change any settings on the toolbar.

2. Click the left mouse button on the footprint to place the port. This will bring up the port property dialog box.

3. Select the device that the port belongs to (see the next secion on Multi-Device Footprints). For example, if this is the second component in a package, choose "B".

4. Choose the "Port Number" as the pin within this device that the port belongs to. For example, if this is pin #3 of an op-amp (the output), type "3".

5. Fill in any other desired options and press OK.

Creating Multi-Device Footprints

Multi-device footprints (bus resistors, etc.) are created by assigning port numbers to different devices within the footprint. The first device (schematic element) within the footprint is usually labeled device "A". For example, the first resistor in a bus package would be device "A". The first pin of device "A" is labeled pin "1", so the port that designates the first pin of device "A" is labeled "A1" on the footprint. This is illustrated in Footprint Example 2.

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Provided Footprint Libraries

y SM782.LIB - footprints taken from the Institute for Interconnecting and Packaging Electronic Circuits SM 782 standard, Revision A, August 1993. IPC may be contacted at 7380 N. Lincoln Ave., Lincolnwood, IL, 60646. This standard is very specific on dimensions for the landing patterns. In general, maximum dimensions were used in creating the library footprints. The silk screens were generated by Eagleware based on general industry convention determined by reviewing several PWBs.

y LEADED.LIB - leaded element footprints. These footprints were generated from data provided by the following manufacturers: Coilcraft, ITT, J.W. Millar, Kyocera AVX, Motorola, Murata, Panasonic, R-Ohm, and Toko. The through holes in this library are typically 20 mils larger than the lead diameter and the pads are 35 mils larger than the through hole diameter. In certain active devices, such as DIP ICs and TO-92 transistors, sufficient spacing was not available and smaller margins were used. The silk screens were generated by Eagleware based on general industry convention determined by reviewing several PWBs.

y HPLIB.LIB - transistor footprints taken from the HP Communications Components GaAs & Si Products data book.

y SAMPLE.LIB - miscellaneous leaded and surface mount footprints for such objects as mounting screws, coplanar grounds, grounds with via holes, grounds with wagon wheel pads and a sample quad operational amplifier.

Certain footprints, such as 14 pin DIP packages, have hundreds of possible uses. It might be a quad opamp or a multiple transistor package. Port assignments in these devices were

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sequential, such as pin 1 through 14. When you use such a device you will need to create a specific footprint with different port numbering. We recommend storing these footprints you create in new libraries. You may create these footprints by loading an existing footprint, modifying as necessary, and Saving As a new name.

Footprint Example 1

0805 Capacitor Footprint

The figure below shows the dimensions for a standard 0805 footprint. This example demonstrates how to create a =LAYOUT= footprint for this device in the footprint editor.

To begin, choose Footprint Editor/New Footprint from the Tools menu.

Set the current units to mils by choosing "Properties" from the Layout menu. Select "Mils" as the current units from the General tab, and press OK.

Pads should be placed first.

To place the first pad:

1. Select the Pad button ( ) from the toolbar, and place the pad anywhere within the editor window.

2. When the "Pad Properties" dialog appears, select "Square/Rect" in the pad shape group.

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3. The width of the pads shown in the figure is 33 mils, so type "33" into the "Pad Width" box. Enter "40.6" as the pad height (also shown in the figure).

4. Select "Metal" in the Layer box to place the pad on metal.

5. Place the pad center at the origin by specifying "0,0" as the location and press OK.

To place the second pad:

1. Repeat steps 1-4 above.

2. Type "48.3, 0" as the second pad location. This sets the center-to-center pad spacing to 48.3 mils as shown in the figure.

3. Click OK.

The silk layer should be placed next.

Note: To prevent silk screen interference with metal layer objects, all silk should be kept at least 10 mils from the nearest metal.

To draw the silk screen

1. Select "Line" from the toolbar. 2. Select "Top Silk" in the toolbar layer combo. This places

the line on the top silk layer. 3. If square ends are shown on the right-most toolbar

button, click the button to change the line shape to round.

4. Select "10 mils" in the toolbar line width combo. If "10 mils" is not available, select "New Width" and add it to the list.

5. Starting at "-31.5,35.3", draw a line to "79.8, -35.3". This includes 10 mils beyond the pad width plus 5 mils for half the silk line width. These start and end coordinates can be simply typed into the line object properties box after the line is placed on the footprint.

6. Press "O" to create a 90 degree line. The figures below show the silk line before and after pressing "O", respectively.

7. Draw another rounded line on silk from "-31.5,35.3" to "79.8, -35.3", press "O", and press "F" to flip the angle. This creates a box around the pads with a 10 mil clearance.

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Silk line before pressing "O":

Silk line after pressing "O":

To place the designator text:

1. Select the Text Button ( ) on the toolbar to place text on the footprint, and select "Top Silk" in the toolbar layer combo. Click the left mouse button near the pads.

2. When the "Text Attributes" dialog appears, type "@DES" in the "Text:" box. This allows the schematic element using this footprint to fill in the element designator on the layout.

3. Select "Use Default Size" to allow the text to be sized later when the footprint is used in a layout.

4. Type "24.15,50.3" for the text location. This centers the text horizontally, and allows a 10 mil vertical clearance for the silk screen box.

5. Specify "Center X" for the x-justification, and "Bottom" for the y-justification. This forces the text to always be centered horizontally, and keeps the 10 mil clearance from the part box. Any other y-justification would allow the text to expand downward with increasing size, breaking the 10 mil separation rule.

6. Select OK. To place footprint ports:

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1. Select "Place Footprint Port" from the Layout menu. Click the left mouse button on the center of the first pad. This places a footprint port on that pad. Press Enter to accept the default settings.

2. Repeat, placing a footprint port on the second pad. The final footprint is shown below.

Footprint Example 2

LF347 Quad Op-Amp Footprint

The figure below shows the dimensions for a Texas Instruments LF347 quad op-amp package. This example demonstrates how to construct a footprint for this device in the footprint editor.

The current units should be set to mils for this example.

The pads should be placed first. Since this is a leaded part, through-holes are needed at each pad location.

In the figure above, the pins are 100 mils apart, so the pad center spacing should be 100 mils. The hole diameter must be at least 21 mils to accommodate the pins, but should not exceed 33 mils, the width of the seating flange. For this example, the pad

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width will be 75 mils, and the through hole diameter will be 30 mils.

The figure below shows a pin-out diagram for the LF347 package.

To place the pads and through holes:

1. Click the Viahole button ( ) on the toolbar to place a viahole and pad.

2. Click the left mouse button within the editor window. The Viahole Properties dialog appears.

3. Choose "Square/Rect" for the pad shape. This will identify pin 1 during assembly. Type "30" for the drill diameter, and "75" for both the pad width and height.

4. Since this is the first pad, set the location to "0,0".

5. Place a via with a round pad at "100,0" to properly space the hole centers. The diameter of the pad should be set to 75 mils, and the hole diameter should be 30 mils.

6. The remaining five pads for the first side should be placed at 100 mil increments as in step #5. The final pad for the first side (labeled pin #7 above) should be placed at "600,0".

7. The remaining holes should be placed at the same x-offset as the first side, with a y-offset of 310 mils (the

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distance given in the first figure above for the pin-to-pin cross dimension). The drill diameter and pad dimensions are the same as before.

Next, the ports should be placed.

y Three ports will be used for each of the op-amps shown in the pin-out diagram. Each op-amp is considered to be a device, so the footprint will have four devices with three ports each.

y The port numbers must be assigned according to the order that the associated schematic element uses. The order can be found on the schematic element's diagram in the Reference manual.

y In the OPA model, the non-inverting input is pin 1, the inverting input is pin 2, and the output is pin 3.

Warning: This port numbering convention must be adhered to when creating a footprint. Otherwise, the rubber-band lines created by =LAYOUT= will indicate erroneous connections that should be made.

To place the ports for the first op-amp:

1. Click the Port button ( ) on the toolbar.

2. Click the left mouse button in the editor window. The "Port Properties" dialog appears.

3. Type "25" into the "Size:" box. This specifies a drawing size of 25 mils for the ports, which should be large enough to see against a 75 mil pad.

4. Assign this port to the first op-amp by choosing "A" in the "Device:" combo.

5. According to the pin-out diagram, this is the output of op-amp "A", so type "3" into the "Port Number:" box. (This assigns the op-amp output to pin #1 on the physical package.)

6. Choose "Metal" in the layer combo. This indicates that =LAYOUT= objects should be on the metal layer before connecting to the pad.

7. This port should be centered on the first pad, so type "0,0" as the location.

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8. Place ports 2 and 1 for device "A" on top of pads 2 and 3 at "100,0" and "200,0", respectively.

Placing the positive power supply port:

1. Place a port at "300,0". Since this port is not assigned to a schematic object, choose "None (*)" in the "Device:" combo. Set the port number to 1.

Placing ports for the second op-amp:

1. Place a port at "400,0". The device should be set to "B", since this is the second op-amp in the package.

2. Set the port number to "1". This corresponds to the non-inverting input.

3. Place two more ports for device "B" at "500,0" and "600,0". Number them ports "2" and "3", corresponding to the inverting input and the output, respectively.

The footprint should look like the figure below at this point.

Placing ports for the third op-amp:

1. Place a port at "600,310". The device should be set to "C", and the pin number set to "3".

2. Place two more ports for device "C" at "500,310" and "400,310", and number them ports "2" and "1", respectively.

Placing the negative power supply port:

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1. Place a port at "300,310". Again, this port is not assigned to a schematic element, so choose "None (*)" in the "Device:" combo. Set the port number to "2".

Placing ports for the fourth op-amp:

1. Place a port at "200,310". The device should be set to "D", and the port number set to "1".

2. Place two more ports for device "D" at "100,310" and "0,310", and number them ports "2" and "3", respectively.

Next, the silk screen should be drawn.

Drawing a silk screen box inside the pad perimeter:

1. Draw a 10 mil line on "Top Silk" from "-32.5,257.5" to "632.5,52.5" and press "O" to create a 90 degree angle. This clears the pads by 10 mils, and extends to the edge of the pads on the open ends of the footprint.

2. Draw another 10 mil line on "Top Silk" from "-32.5,257.5" to "632.5,52.5", press "O", and press "F" to flip the angle.

Placing the designator text:

1. Click the Text Button ( ) on the toolbar and click the left mouse button within the editor window.

2. Type "@DES" in the "Text:" box and select "Use Default Size".

3. Select "Top Silk" in the "Layer:" combo.

4. Set the location to "300,357.5", and select "Center X" and "Bottom" y justification.

5. Click OK.

Labeling the type of package:

1. Click "Text" on the toolbar and click the left mouse button within the editor window.

2. Type "LF347" in the "Text:" box and type "65" in the "Text Size:" box. This text will not change size with the default settings, and will always be the width of the silk screen box.

3. Type "90" in the "Angle:" box. This will rotate the text counter-clockwise 90 degrees.

4. Select "Top Silk" in the "Layer:" combo.

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5. Set the location to "-47.5,155", and select "Center X" and "Bottom" y justification. This places the text at the left edge of the silk screen box with a clearance of 10 mils.

6. Click OK.

The footprint is now complete. The figure below shows the final footprint.

Chapter 12: Simulations/Data

Simulations / Data

GENESYS supports several different types of simulations, allowing the exploration of a complete range of circuit performance:

y DC Simulation (nonlinear)

y Linear S-Parameter Simulation

y Planar 3D Electromagnetic (EM) Simulation

y Harmonic Balance Simulation (nonlinear)

y Parameter Sweep

y Link To Data File

Several of these capabilities work together. EM co-simulates with either the nonlinear or linear circuit simulator, bringing the accuracy of EM analysis of metal with the generality and speed of circuit simulation. Parameters sweeps can be used with DC, linear, and nonlinear simulation as well as with other sweeps. Frequency, resistance, substrate height, and DC supply level are just a few of the parameters that are typically swept.

All of these simulations can be added to a workspace by right-clicking the Simulations/Data node on the Workspace Window.

Which Simulator Should I Use?

Often, we at Eagleware are asked which simulation method should be used in a particular circuit: Linear (SuperStar)? Nonlinear (HARBEC)? SPICE (by exporting)? Electromagnetic (EMPOWER)?

For most circuits, you will use a combination of the different simulations. We have developed several guidelines that should simplify the decision for most applications. First, each method has benefits and drawbacks:

Linear SPICE Electromagnetic HARBEC

Benefits Extremely fast Time

domain Extremely accurate Steady-State

Nonlinear

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Schematic or netlist entry

Schematic or netlist entry

Does not require an intimate knowledge of the circuit – simulator figures out coupling, etc.

Study mixing, compression and intermodulation

Real-time tuning of circuits

Starting waveforms (e.g. oscillator startup)

Can predict radiation, current distribution.

DC biasing information

Uses manufacturer-provided measured data

DC biasing information

Automatic deembedding

Lots of vendor-supplied models

Requires very little memory

Lots of vendor-supplied models

Predicts box mode effects (e.g. What happens if the circuit is placed in a box?)

Use frequency dependent equations and post-processing

Easily use equations and user functions

Non-linear modeling of crossover distortion, etc.

Can use arbitrary shapes – does not require an existing model for them

Use measured data in simulation

No time domain

Very slow Extremely slow Much slower than linear

No biasing information

Very hard to model frequency domain behavior (e.g. unloaded Q)

Requires lots of memory

Takes a lot of memory and time

Everything is linear

No distributed models (e.g. microstrip, waveguide, etc.)

Discretizes metal patterns to fit grid

Requires nonlinear models Drawbacks

Requires knowledge of circuit – coupling factors, parasitics, etc.

Requires knowledge of circuit – coupling factors, parasitics, etc.

Can be difficult to set up a circuit for simulation

Cannot study transient behavior (for example, oscillator startup)

In determining which simulation type to use, several points should be considered:

Linear or Electromagnetic?

1. What is the highest frequency used in the circuit? If below about 1 GHz, lumped elements are often used in

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place of distributed elements. In this case, the final board layout usually won’t add any significant parasitics or coupling concerns. Often, however, customers use EMPOWER to simulate the final board layout to make sure that it doesn’t differ from the linear simulation.

2. How big is the circuit? If the circuit itself is very small compared to a wavelength at the highest frequency of concern, electromagnetic simulation may not be needed. This is because resonances occur at quarter wavelengths, and circuits much smaller than this usually behave as predicted by a complete linear simulation.

3. Does the circuit have non-standard metal shapes, patterns, or geometries? If so, electromagnetic simulation may be the only option. EMPOWER can simulate any arbitrary shape, such as ground plane pours. A linear simulator requires a netlist or schematic to describe the circuit, so models would have to exist for the pattern that you plan to simulate.

4. Do any of the models in the circuit exceed or come close to exceeding the published parameter ranges for SuperStar? If so, you may want to verify the SuperStar simulation with EMPOWER, or use EMPOWER exclusively. Most of the models in SuperStar were derived from measured data, which was only taken for particular parameter variations. The allowed parameter ranges are published for each model in SuperStar.

Linear or Harmonic Balance?

This question is the easiest to answer: for active circuits you will usually use both. For passive circuits (filters, couplers, power dividers, etc), you will only use linear. Passive circuits are linear-harmonic balance will not give you extra information that you could not get from linear simulation. Active circuits are inherently nonlinear. Harmonic balance will help you analyze DC operating points and nonlinear performance.

For both active and passive circuits, linear simulation is the workhorse of RF design. Matching, noise, and stability studies are all completed quickly using linear simulation. Harmonic balance is used to complete the analysis of most circuits. Examine mixer conversion gain, amplifier compression, and detector efficiency using harmonic balance.

Linear or SPICE?

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Often, this question does not have a quick answer. For example, many engineers associate SPICE with time domain simulation, and a linear simulator with frequency domain simulation. Actually, many circuits have data of interest in both the time and frequency domains, which could warrant the use of both simulators. For example, an oscillator has phase noise, transmission, and phase characteristics, which are all frequency domain measurements. Oscillators also have waveform magnitude, starting time, and startup transients, which are all time domain measurements. In this case, both simulators can be used in the circuit design.

There are some guidelines for deciding between SPICE and linear simulation:

1. Does the circuit depend on time domain characteristics? If so, SPICE must be used for this portion of the design. If the circuit depends entirely on the time domain, SPICE can be used exclusively. However, if a frequency domain response is also of interest, linear simulation may be used in addition to SPICE.

2. What is the highest frequency of concern in the circuit? If it’s over about 100 MHz, you may want to use linear simulation. This is because component unloaded Q becomes a concern above this frequency, and SPICE does not have the built-in ability to include this effect in simulations. If the frequency is much higher than this, linear simulation is almost a must since SPICE uses lumped element models for RF parts, which do not usually model high frequency effects accurately.

3. Is the circuit all lumped elements? If so, SPICE may be used. However, unloaded Q is not built into SPICE, so guideline #2 must be considered.

4. Does the circuit contain distributed parts? If so, linear simulation is a must since SPICE does not include distributed models. The electrical transmission line models in SPICE can be used, but for final verification of the physical implementation of the lines, linear or electromagnetic simulation should be used.

Often, both SPICE and linear simulation are useful in a design. For example, in amplifier design, the linear portion (gain, matching) can be done in SuperStar, and the device biasing can be done in SPICE.

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Linear Simulation

Linear simulation calculates S-, Y-, Z-, and H-parameters of a circuit. It is a small signal analysis that assumes that the circuit is operating in the linear region. Active devices such as transistors and diodes can be modeled either with S-parameters (measured or provided by a manufacturer) or a nonlinear model. If a nonlinear model is used, GENESYS automatically runs a DC analysis to determine the circuit operating point, linearizes the nonlinear circuit around the operating point, and uses that linear model in the analysis.

To add a linear simulation:

1. Right-click the Simulation/Data node on the Workspace Window.

2. Select "Add Linear Simulation".

3. Complete the Linear Simulation Properties dialog. For more information, see the Reference manual.

Link To Data File

A "Link to Data file" allows you to plot data from a device data file without drawing a schematic or creating a netlist.

To add a data file import:


2. Select "Add Link To Data File".

For information on the Data File Import Setup dialog, see the Reference manual. For an example, see "Model Extract.WSP".

Planar 3D Electromagnetic Simulation

Electromagnetic simulation in GENESYS is provided by the EMPOWER simulator.

To add an electromagnetic simulation:

y Right-click the Simulation/Data node on the Workspace Window.

y Select "Add Planar 3D EM Analysis".

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For information on the EMPOWER Options dialog, see the Reference manual. For other information about EMPOWER, see your EMPOWER manual.

Parameter Sweep

3D graphs in GENESYS require parameter sweeps to generate a third dimension for plotting. Parameter Sweeps give you this third dimension be adjusting a tuned variable, repeating another simulation for each adjustment. For example, to see how the response of a circuit changes when a capacitor is adjusted, you can add a Parameter sweep which sweeps the linear or electromagnetic simulation while adjusting the capacitor value. You can then view the results on a 3-D graph.

To add a parameter sweep:


2. Select "Add Parameter Sweep".

3. Add a Table or 3-D graph to display the results.

For advanced applications, you can nest Parameter sweeps, creating 4-D, 5-D, or higher data. This data can then be viewed on a table.

For information on the Parameter Sweep Properties dialog, see the Reference manual.

DC Analysis Overview

DC simulation analyzes the static operating points (DC voltages and currents) at each nonlinear node and port in the circuit. When designing circuits using non-linear models, you should always check the DC operating point before doing linear or harmonic balance simulations. DC analysis is very fast and will make sure that you have entered a workable design.

Note: DC Simulation is not generally the same as the DC (zerofrequency) level from a harmonic balance simulation. In DC simulation, allAC sources are turned off.

Nonlinear device models have many parameters that can be entered in error. To make sure that the model is correct, it is a

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good idea to look at the DC characteristic curves of the device before entering acomplete circuit. Workspace templates are available (Select New From Templatefrom the File Menu) that make it easy to create thesecurves.

In addition to analysis, DC results can be optimized. For example, you can optimize bias resistor values to achieve a desired collector current and voltage for a bipolar transistor. See the walkthrough DC Analysis - Verifying TransistorParameters for an example.

To add a DC simulation:


2. Select "Add DC Analysis"

3. Complete the DC Analysis Properties dialog box. For details, see the Reference manual.

Harmonic Balance Overview

The HARBEC harmonic balance simulator simulates the steady-state performance of nonlinear circuits. Circuits can be stimulated with a variety of periodic signals (voltage, current, and power) such as single CW tones, pulsed waves, or dual tones. Complex waveforms can be constructed by combining various periodic signals; HARBEC makes this through thecustom voltage and current sources. The two assumptions that harmonic balance uses are 1) the signals in the circuit can be accurately modeled using a finite number of spectral tones and 2) the circuit has a steady-state solution.

HARBEC works by solving Kirchoff's current law in the frequency domain. It applies the stimulus sources to the designed network. It then searches for a set of spectral voltages that will result in currents that sum to zero at each node and each frequency in the circuit. It adjusts the voltage levels (a spectrum of voltages at each node) through a variety of methods until the sum of the currents is less than a user-specified level (see "Absolute Error" and "Relative Error" on the Harmonic Balance dialog box in the Reference Manual). This process of searching is known as "convergence." The length of time it takes to take a search step is roughly equal to the cube of the product of the number of frequencies and the number of nonlinear nodes. Thus, if you double the number of frequencies in the circuit, you can expect

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the solution to take roughly 8 times longer. However, this is only a rough estimate. The convergence process is complexand difficult to predict.

At a fundamental level, harmonic balance solves a simultaneous set of nonlinear differential equations. No mathematical approach is guaranteed to find a solution to the problem. Years of work have gone into HARBEC to develop the most robust strategies available.

To add a harmonic balance simulation:


2. Select "Add Harmonic Balance Simulation"

3. Complete the HARBEC Options dialog box. For details, see the Reference manual.

HARBEC Popup Menu

Rename - Allows the name of the icon to be changed

Delete This Simulation/Data - Removes the icon and all of its associated data from the system.

Recalculate Now - Starts a simulation if required. If the simulation is up-to-ate (no changes have been made to the

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design since the last simulation), this command will be "gray" and the simulation will not be re-run. Toforce a new simulation, either make some change in the design or select"Delete internal simulation data".

Mark results up-to-date - Changes the status of a simulation to current. Use this feature when a change has been made to the design that does not affect the simulation results (such as changing a value and then changing it back).

Automatically Calculate - Toggles on or off the state that starts a simulation any time a change is made to the design.

Active for Opt/Yield/Recalc - Toggles on or off the simulation status. If not Active, the simulation will not be run when during optimization, yield analysis, or when the recalculation button is clicked.

Write all internal data - Creates a set of external ASCII files containing the simulation netlist, the simulator log messages, raw simulation results, and simulation errors.

Delete internal simulation data - Discards all existing calculated results. Selecting this menu will cause the simulator to start from a new state on its next run.

Properties - Opens the HARBEC Options dialog box

Show HARBEC monitor window - Opens a window that contains detailed information about the HARBEC simulation run. Only available for harmonic balance simulations.

Entering Nonlinear Models

GENESYS supports four different way to enter nonlinear models:

y Direct Schematic Entry

y Single Part Model

y Nonlinear Model Library

y SPICE Link

The simple way is to enter a nonlinear model is through direct schematic entry. You place a nonlinear device, such as an NPN transistor, from the schematic tool bar. Then double-click the device and type in the device parameters. The advantage of this technique is that it is simple. The disadvantage is that it is not as easy to reuse the device in another design.

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Another way to enter a nonlinear model is to create a single part model. This is similar to using a model statement in other simulators. See the Designs: Single Part Model chapter in this User's Guide for details.

A third way to enter nonlinear models is to choose one from the supplied library of parts. To do this, just enter the base nonlinear model that you would like (for example, a PNP), then change the model to the desired part using the "Model?" button on the element parameter dialog.

The final way to enter a nonlinear part is to link the model to a SPICE netlist. GENESYS can read SPICE 3 compatible netlists, extracting models and subcircuits. Most vendors supply nonlinear models, including package parasitics, in the form of SPICE netlists. One advantage of SPICE links is that complex models can be included very easily in the simulation. The chance of error in entering numbers is reduced. The disadvantage of the link is that parameters are difficult to view and cannot be tuned or optimized. See the Designs: Link to Spice File chapter in this User's Guide for details.

DC Analysis - Verifying Transistor Parameters

The first step is to create a schematic of the transistor with variable collector voltage and base current to verify the transistor IV curves with the manufacturer's published data.

1. After starting GENESYS, right click on the schematic "Sch1", select "Rename" and change the name to DC Curves . Click OK.

2. Click "Non-Linear" from the toolbar to open the Nonlinear toolbar, select an NPN transistor (BIPNPN) and place in the center of the schematic. Double-click on the transistor to show the dialog box, but leave all values blank. We will use an ideal transistor for this example, however you can specify a specific model for your applications by clicking on the "Model" button. Click OK.

Note: To place a specific manufacturer's transistor model, you first place the appropriate picture, then change the model for the part to a device model.


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3. Click on the "Source" icon in the toolbar, select "Current Probe (Ammeter)" and place it on the collector of the transistor. Enter Designator: IC. Click OK. Use Edit/Mirror (F6), if necessary, to show the current flow into the collector or the transistor and/or Edit/Rotate (F3) to rotate the ammeter.

4. Select a DC voltage source from the toolbar, place it on the other side of the ammeter and enter DC Voltage: ?1, Designator: VC. Click OK.

5. Click on the "Source" icon in the toolbar, select "Source: DC Current". Enter Current: ?5e-6, Designator: IB. Click OK. Press F6, if necessary, to show the current flow into the base of the transistor.

6. Press "G" on the keyboard (or press the ground button on the toolbar) and place a ground on the other end of the current source. Click OK.

7. Press the "Space Bar" (reselect previously placed parts) and place another ground on the emitter of the transistor. The schematic should look like the following (without the DC bias voltages and currents shown):

8. Save your file now and remember to save frequently.

9. In the Workspace window, right click on the "Simulations/Data" node and select "Add DC Analysis". Accept the default name by clicking "OK".

10. Click the "Annotate" checkbox and press OK to show DC voltages on the schematic.

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11. Right click on "Simulations/Data" again, and this time select "Add Parameter Sweep". Name the sweep Vc Sweep .

12. Enter the following values as shown below: Simulation to Sweep: DC1, Variable to Sweep: V,Vc, Type of Sweep: Linear: Number of Points , Start value: 0, Stop value: 3, Number of Points: 20. Click OK.

13. Add another parameter sweep for the base current sweep and name it Ib Sweep .

14. Enter the following values as shown below: Simulation to Sweep: Vc Sweep , Variable to Sweep: IDC,Ib, Type of Sweep: Linear: Number of Points , Start Value: 2E-6, Stop Value: 10e-6. Number of points: 5. Click OK.


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15. Right click on the "Outputs" node in the Workspace window and select "Add rectangular graph". Name the graph "DC Curves".

16. Enter Default Simulation/Data or Equations: Ib Sweep.DC Curves, Measurement: iic, Unclick "Auto-scale" in the Left Y axis, Enter Min: 0, Max: 1.5e-3, # of Divisions: 5. Click OK. (Measurement IIC means current (I) at probe IC.)

17. Click the Calculator icon in the toolbar and the graph displays DC curves for the transistor as shown below. These can be compared to manufacturers data to verify correct data entry or model accuracy.

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DC Analysis - Biasing the Transistor

This walkthrough continues from the DC Analysis/Device Verificationwalkthrough. The next step is to properly bias the transistor. For this example, we arbitrarily chose a collector voltage of 2.5 volts and an Ic of 10ma.

1. Right click on "Designs/Models" and select "Add a Schematic". Name the schematic DC Bias and click OK.

2. In the Workspace window, double click on the "DC1" simulation and click the "Annotate" box for the DC Bias schematic.

3. Go to the "DC Curves" schematic and select "Select All" from the Edit menu to select all components. Select Copy from the Edit menu.

4. Go to the "DC Bias" schematic and select Paste from the Edit menu.

5. Double click on VC and change the DC Voltage to 5. Click OK. While VC is still highlighted, hold the "Alt" key down, to disable "Keep Connect". Use the "Up" arrow key to move VC up six spaces to make room for a resistor.

6. Delete current source IB and related ground.

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7. Press the "R" key on the keyboard and place resistor R1 between VC and the ammeter. Make R1's resistance ?100. Press the "R" key again or the "Space Bar" and place R2 as shown below. Make R2 ?100 also.

8. Press the "W" key to place a wire and connect R2 to the transistor base. The schematic should look as shown below.

9. In the Workspace window, under "Simulations/Data", right click on the "VC Sweep", and de-select the "Active for Opt/Yield" to turn this off. Do the same for the "IB Sweep". This will prevent these sweeps from calculating during the optimization we are about to perform.

10. In the Workspace window, right click on Optimizations node and select "Add a Set of Targets".

11. Accept the default name.

12. Enter the following: Default Simulation/Data or Equations: DC1.DC Bias , On the first line enter: Measurements: v2 Op: =, Target: 2.5, Weight: 1, Min: 0, Max: 0. On the second line enter: Measurement: iic , Op: =, Target: 0.01, Weight: 100, Min: 0, Max: 0. (Min and Max can actually be omitted in this case, as there is no frequency/parameter range with a DC sweep).

Note: v2 is the voltage at the transistor collector (node 2). If the collector is a

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different node, change the "2" to the collector node number.

13. Click on "Optimize Now" and select "Automatic". The optimizer will run until it selects the correct values of R1 and R2 to meet the targets. When the error in the status window is close to zero, press "ESC" to stop the optimization.

14. We then select standard resistor values closest to the optimized values. For 1% resistors, R1=243 ohms and R2=16.5kohm. Double click on R1 and R2 and change resistance to 243 and 16500 respectively.

Linear S-Parameter Simulation Example

Now that we have the transistor verified and properly biased from theprevious DC walkthroughs, we can add the input and output and verify the input and output match.

1. Right click "Designs/Models" and select "Add a Schematic". Name the schematic "Amplifier" and click OK.

2. Copy and Paste the "DC Bias" schematic to the "Amplifier" schematic.

3. Press the "C" key on the keyboard and place capacitor C1 on the transistor collector. Enter Capacitance: 100. Click OK. Press the "C" key again or the "Space Bar" and place C2 on the transistor base. Enter Capacitance: 100. Click OK.

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4. Select the "Input: AC Power (PAC)" from the toolbar and place at the end of C2. Enter the values: Designator: IN, Source Frequencies: 900, AC Power: IN as shown below.

Note: Multiple frequencies (and corresponding power and phases)can be entered by separating the values with semi-colons, e.g., 900;910 for 900and 910 MHz.

5. Double click on Source VC. Change DC Voltage to VC, a variable to be entered in the next step.

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6. In the Workspace Window, double click on the Equations node. Type: VC=?5 IN=?-40 and close the equations window.

7. Place an output at the end of C1 and click OK to select the default values.

8. In the Workspace window, right click on Simulations/Data node and select "Add Linear Simulation". Accept the default name. Click OK.

9. Click OK again to accept the default input values.

10. In the Workspace Window, right click on Outputs node and select "Add Smith Chart". Name the Graph Match .

11. Add S11 and S22 to the measurement list and press OK. You will see a Smith chart with input and output match.

HARBEC Analysis Walkthrough

This walkthrough continues from the Linear Simulation walkthrough.

1. In the Workspace Window, right click on Simulations/Data node and select "Add Harmonic Balance Simulation". Accept the default name. Click OK.

2. Enter Design to Simulate: Amplifier , Order: 5 and click OK.


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3. In the Workspace Window, right click on Outputs node and select "Add Rectangular Graph". Name the Graph Spectrum .

4. Enter the following: Default Simulation/Data or Equations: HB1.Am plifier , Measurement: P1.

5. Click OK. Click the Calculate icon in the toolbar and the graph displays the input spectrum as shown below.

Note: The input spectrum shows higher than expected because theinput is not matched. This measurement works more intuitively on outputports.

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6. In the Workspace Window, right click on Outputs node and select "Add Rectangular Graph". Name the graph Waveform .

7. Enter the following: Default Simulation/Data or Equations: HB1.Amplifier, Measurement: line1: time[v2] , line 2: time[v1] .

8. Click OK and the graph displays the input and output waveforms as shown below.


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9. In the Workspace window, right click on the "Simulations/Data" node and select "Add Parameter Sweep". Name it Input Power Sweep .

10. Enter the following values as shown below: Simulation to Sweep: HB1, Variable to Sweep: IN. Type of Sweep: Linear: Number of Points, Start Value: -40, Stop Value: 0. Number of points: 10. Click OK.

11. In the Workspace Window, right click on Outputs node and select "Add Rectangular Graph". Name the Graph Output vs. Input Power .

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12. Enter the following: Default Simulation/Data or Equations: Input Power Sweep.Amplifier , Measurement: P2@900.

13. Click OK. Click the Calculate icon in the toolbar and the graph displays Output Compression as shown below.

Linear vs. Nonlinear Device Models

S-parameters for RF and microwave devices are commonly available and easy to measure with a network analyzer. They are the most accurate way to model the small-signal performance of circuits. However, they are only valid at a particular operating point (bias level). Nonlinear device models are also commonly available from manufacturers but they are harder to extract from measurements. The advantage of nonlinear models is that they model circuit performance at all bias levels and frequencies. Moreover, the model characterizes the complete linear and nonlinear performance of the devices, including effects such as compression and distortion.

Typical Harmonic Balance Measurements

Compression To calculate compression of a circuit (a decrease in circuit transmission gain), use a parameter sweep to increase the

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power from a low level through compression. Assuming that the power input is on port 1 and the output is on port 2, the picture below shows how to plot the output power and the gain. Note that the default simulation is set to the power sweep. The first trace is P2@900, meaning the power at port 2 at 900 MHz. The second trace is the gain. Note that this is an inline equation. It starts with an equals sign, and the data is referred to by operator (the dBm operator is required in the equation, it is not needed as a direct plot as in trace 1).

Solving Convergence Issues

The simulator searches for a solution until the user-specified accuracy is reached, or until a specified number of searching steps. Sometimes you might run into convergence issues. Below are a few steps that you can use to improve convergence results. Each of the parameters below is changed on the Harmonic Balance (HARBEC) Options dialog box:

1. Increase the number of frequencies (the order) used in analysis. If not enough frequencies are used, the data is being undersampled and cannot accurately represent the solution. For example, modeling a square wave with three harmonics will ignore a lot of energy in the circuit, often leading to convergence issues. Increasing the number of frequencies analyzed will more accurately model the signals (at the expense of more time).

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2. Try "Always" and "Never" options for calculating the Jacobian. If a Jacobian is calculated, the simulator will search in a different direction from the Fast Newton method. Sometimes the Jacobian will be a better direction, sometimes it will be worse. Try both approaches.

3. If the convergence issue occurs during a parameter sweep, sweep more points so that that each simulation is closer to the previous one, often requiring less total time. Or, if this is not practical or desired, turn off "Use Previous Solution As Starting Point." This will cause the simulator to start fresh with each new parameter value.

4. Increase the value of Absolute Tolerance and Relative Tolerance. This should speed up the solution but will be less accurate, particularly for low signal levels.

Optimizing Simulation Performance

A variety of methods and parameters are available to control the approach that HARBEC uses to find convergence. The speed of performance can be improved by adapting these parameters to the specific circuit being analyzed. To understand how these parameters work, it is useful to understand a little about how the simulator searches.

To find a solution, the simulator uses a Newton-Raphson search to find the solution. It starts with an initial guess and calculates an error function. The derivative of the error function is used to extrapolate the next point. In harmonic balance, partial derivatives exist for every node and every frequency. The full matrix of partial derivatives is known as aJacobian.

Jacobian Calculation

The full Jacobian is usually the most accurate way to determine the next point. However, the matrix can be very large, requiring a lot of time to calculate and invert. To make the simulator faster, HARBEC generally tries Fast Newton steps first. A Fast Newton step calculates only a portion of the Jacobian and uses it to calculate the next point. For many circuits, the entire solution can befound quickly using only Fast Newton steps.

The default setting for HARBEC is to automatically switch between using Fast Newton and full Jacobian steps. Artificial

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intelligence techniques are used to determine which technique to use, and when. Usually, the automatic switching will find the solution quickly. However, for certain circuits, it will be better to always use the Jacobian or never use the Jacobian. On the HARBEC Options dialog box, you can specify either "Automatic," "Always," or "Never" use of the Full Jacobian. Experimenting with different values may improve convergence speed.

Order vs. Accuracy and Time

The easiest way to affect simulation performance is to change the order of the frequencies used in simulation. Harmonic balance models signals in the circuit by using a finite number of harmonics of the fundamental signals and a finite number of mixing terms. The larger the number of harmonics and mixing terms, the better the approximation of the actual signals. However, the larger the number of frequencies the longer the simulator takes to work. The length of time to take a search step is roughly proportional to the cube of the number of frequencies. So, doubling the number of frequencies will take about 8 times longer to simulate.

However, if not enough frequencies are present to adequately model the signals, then the results will not be accurate. Moreover, the simulator may have difficultly converging if not enough of the energy in the circuit is modeled.

The best practice in selecting order is to start with a reasonable number of harmonics of each signal (typically 5 is a good point), then increase the number until the results stop changing. ("Order" and "Maximum Mixing Order" on the HARBEC Options dialog box control the number of terms.) In this way, you can make tradeoffs of speed versus accuracy.

Amplitude Stepping

To start the search for convergence, HARBEC analyzes the circuit at DC, this is, with all independent AC signal turned off. Using DC as a first guess, it turns on the signals to "Maximum Amplitude Step" percentage of full signal. If convergence is reached at this step, it takes another equal step. If convergence is not reached, it decreases the step size and tries at the lower signal level. Some circuits will converge in a single 100% step. Others will require a smaller step to find the solution. If a smaller step is required, it will be faster to start with that step. If the step size is too small, the simulator may waste time calculating

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intermediate steps to find the final solution. Convergence speed can be improved by setting "Maximum Amplitude Step" to the ideal step.

Krylov Subspace Iterations

When the Jacobian matrix gets very large, it can become very slow to calculate and use. Krylov subspace iterations can dramatically reduce the size of the matrix and thus speed up calculations of very large circuits. In general, however, Krylov will have more convergence issues than full Jacobian steps. Also, for smaller circuits, Krylov may be slower than full Jacobian steps. For very large problems, try selecting Krylov to reduce memory requirements and speed convergence.

See Also: HARBEC Options dialog reference in the Reference manual.

Chapter 13: Measurements (Output Parameters)

Overview

Measurements are covered in-depth in the Reference manual. See the Measurements and S-Parameters chapters for more information.

Chapter 14: Outputs

Overview

All results in GENESYS are shown in Output windows. Outputs display data from measurements taken from Simulations/Data. There are 6 types of outputs (ways to display data) in GENESYS:

y Rectangular Graph

y Smith Chart

y 3D Graph

y Polar Chart

y Variable Viewer

y Table

Creating an Output

There are two ways to create an output in GENESYS:


1. Right-click on the Workspace Window "Outputs" node as shown in the figure below.

2. Select the desired output type.

With the Outputs Manager:

1. Open the Ouptuts Manager by choosing "Outputs..." on the Workspace menu.

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3. Select the desired output type.

Opening an Existing Output

To open an existing output:


y Double-click the desired output under the "Outputs" node.

From the Outputs Manager:

y Double-click the desired output in the list, or

y Select the desired output and click the "Open" button.


Property Dialogs

Property Dialogs are a collection of attributes specific for a particular output type. For example, a rectangular graph has both vertical and horizontal axis ranges. The Property dialogs are shown to allow user customization when an output is initially created.

Properties dialogs are available for all output types except Variable Viewer. To view the properties for any output:

y Double-click anywhere in the output, or

y Right-click the desired graph in the Outputs node of the Workspace Window, and choose "Properties", or

y Select the desired output in the Outputs manager, and choose "Properties".

For more information on specific properties available, see the Reference manual.

Markers

Markers can be added to any graphical output except the 3D graph:

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y Rectangular Graph

y Smith Chart

y Polar Chart

To add a marker, click the left mouse button on or near a data point on the graph. For example, here is a graph before clicking the left mouse button:

Here is the graph after clicking:

Whenever a marker is "current", the marker text colors are inverted (white on a colored rectangle). The figure below shows two markers. The one on the right is current.

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Markers are manipulated through the keyboard:

y Delete - deletes the current marker.

y Arrow keys - tune the current marker up or down in frequency.

y Tab - cycles through markers, making each one current.

Markers can be made current by clicking on them, or by cycling with the Tab key.

Note: If you do not like the small circles/squares/triangles which show each data point, you can uncheck "Show Data Points On New Graphs" in the General Options dialog, accessed from Options in the Tools Menu.

Zooming On Smith And Polar Charts

Both Smith Chart and Polar Charts can be zoomed in or out.

y To zoom in, click the Zoom In button ( ), or press Ctrl+Page Up.

y To zoom out, click the Zoom Out button ( ), or press Ctrl+Page Down.

y To maximize the display, click the Maximize button ( ), or press Ctrl+Home. This zooms to fit all traces.

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y On the Smith Chart, you can zoom to the chart

boundaries by clicking the Zoom To Page button ( ), or press Ctrl+End.

Tip: Use Ctrl+LeftArr ow, Ctrl+RightArrow, Ctrl+UpArrow, and Ctrl+DownArrow to scroll a Smith chart

Annotating Graphs

Annotation objects allow text and graphics to be added to graphs, as in the figure shown below:

In this graph, the circle, arrow, text, and balloon text were created with annotation objects. Annotation Objects can be used in any graphical output:

y Rectangular Graph

y Smith Chart

y 3D Graph

y Polar Chart

All annotation objects are placed from the annotation toolbar. To display this toolbar:

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1. Right-click inside the graph.

2. A popup menu appears.

3. Click Toolbars/Annotate Toolbar, as shown below.

4. The Annotate Toolbar appears, as shown below.

The buttons on this toolbar are:

1. Draws a rectangle.

Draws a circle.

2. Draws an arrow or line.

3. Draws an arc.

4. Imports a picture from an external file.

5. Draws a rectangular text area for typing text.

6. Same as #6, except on corner has an arrow for pointing.

7. Changes the background color.

8. Changes the foreground color.

9. Copy/Paste and arrange functions.

10. Groups annotation objects together.

11. Ungroups previously grouped objects.

12. Flips the selection vertical.

13. Flips the selection horizontal.

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14. Rotates the selection clockwise.

15. Rotates the selection counter-clockwise.

16. Displays properties for the selected item.

Rectangular Graphs

A rectangular graph is a cartesian coordinate plot. Rectangular graphs are used to display two dimensional data versus frequency (e.g. magnitude or phase of a complex measurement, but not both). In the figure below, the group delay of a bandpass filter has been plotted. The dashed vertical red lines in the figure above are frequency markers, and can be added to any rectangular graph. For more information on markers, see Markers.

An example is shown below:

By double-clicking anywhere inside the graph, the properties dialog is shown. An example is shown below.

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This sample graph properties dialog box indicates several things:

y The Simulation/Data and design to be used are "Linear1" and "FILTER".

The group delay of S21 is to be shown on the left Y-Axis.

y The left Y-Axis has been set to range from 0 to 50 nanoseconds with 10 divisions.

For a complete description of the objects and properties in this dialog, see the Reference manual. For information on putting extra text and graphics on graphs, see Annotation Objects. For information on creating a Rectangular Graph, see Creating An Output. For information on measurements, see the Reference manual.

3D Graphs

A 3D graph is used to display a measurement versus frequency versus a parameter sweep. Any tunable parameter or variable can be swept. In the figure below, the input reflection coefficient of an antenna matching network is displayed from 3.5 to 3.6 MHz as an inductor in the network is varied (swept) from 250 to 4000 nH. For information on sweeping parameters, see Parameter Sweeps.

Note: 3D Graphs require a Parameter Sweep to generate the three-dimensional data.

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By double-clicking anywhere inside the graph, the properties dialog is shown. An example is shown below.

For a complete description of the objects and properties in this dialog, see the Reference manual.

For information on putting extra text and graphics on graphs, see Annotation Objects.

For information on creating a 3D Graph, see Creating An Output.

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Smith Charts

A Smith chart is used to display complex data, such as s-parameters or impedances. In the figure below, s11 (input reflection coefficient) has been plotted on a Smith chart. The horizontal axis on a Smith chart represents real numbers from zero to infinity, and numbers off the horizontal axis represent numbers having a nonzero imaginary part.


The Smith Charts in GENESYS have two grid options:

1. Impedance

2. Admittance

Both grids can be enabled or disabled from the Properties dialog:

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For a complete description of the objects and properties in this dialog, see the Reference manual. For information on creating a Smith Chart, see Creating An Output. For help on Smith Charts in general, see the S-Parameters section of the Reference manual. For information on which measurements are appropriate on a Smith chart, see the Measurements section of the Reference manual.

Tip: You can scroll a zoomed-in Smith Chart by holding down the "Ctrl" key and pressing the arrow keys.

Polar Charts

A polar chart is used to display complex data, such as s parameters or impedances. In the figure below, s11 (input reflection coefficient) and s22 (output reflection coefficient) have been plotted. The horizontal axis on a polar chart represents purely real numbers, while the vertical axis represents purely imaginary numbers. Numbers that lie between the two axes have both imaginary and real components.

Polar charts and Smith charts will generate the same plots for S-Parameters; only the background and scales are changed. Additionally, some parameters unavailable on Smith Charts can be plotted on a polar chart (such as Y-Parameters).

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By double-clicking anywhere inside the graph, the properties dialog is shown. An example is shown

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below.

For a complete description of the objects and properties in this dialog, see the Reference manual.

For information on creating a Polar Chart, see Creating An Output. For information on measurements, see the Measurements section of the Reference manual.

Variable Viewer

A variable viewer is added to view variable values from the workspace global equations. An example is shown below.

A Variable Viewer can be added from the Outputs node on the Workspace Window, or from the Outputs Manager.

For information on creating a Variable Viewer window, see Creating An Output.

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Tables

Tables are used to provide text-based tabular output instead of graphical output. Any measurement can be placed in a table. In the figure below, the input impedance of a network and the input VSWR is shown.

By double-clicking anywhere inside the table, the properties dialog is shown. An example is shown below.

For a complete description of the objects and properties in this dialog, see the Reference manual. For information on creating a

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Table, see Creating An Output. For information on measurements, see the Measurements section of the Reference manual.

Chapter 15: Equations

Equations

GENESYS includes the ability to define component values by algebraic equations. The Equations provide a rich set of mathematical functions, operators and control statements with automatic parsing. This language significantly enhances the power and flexibility of circuit simulation. It provides for simple features such as gang-tuning and more complex features such as user-created functions and post-processing.

This chapter first gives a few examples of circuits which use the Equations section. A reference section containing descriptions of all capabilities is in the Reference Manuals.

Entering Equations

To enter equations, simply double-click on the Equations node in the Workspace Window and type your equations. To use equations in a schematic, you should first enter any necessary expression into the Equation window. Next, place the parts on the schematic. When entering the values into the component’s dialog box, type a variable name or formula in place of a part value.

Viewing Variable Values

Values calculated in the Equations text may be viewed to verify that the equations yield expected results. Create a Variable Window output. For information on creating output windows, see Creating Outputs.

Bandpass Filter With Equations

The circuit shown in the figure below is a top-C coupled bandpass filter (filename: "Equation Example.WSP"). Normally the user computes filter component values manually or with FILTER, and these constant values are used in the schematic. In the Equations section, equations which define the inductor and capacitor values can be embedded right into the workspace file.

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GENESYS then computes filter component values from other variables such as the filter center frequency and bandwidth.

The workspace for this example is shown below.

The Equations text is duplicated below:

Fo=?100 ' Center frequency in MHz BW=?25 ' Bandwidth in MHz QL=?120 ' Inductor unloaded Q Qbp=Fo*1E6/(BW*1E6) ' Filter loaded Q Q1=1.301*Qbp QN=Q1 K12=.703/Qbp K23=.536/Qbp L=50/(2*PI*Fo*1E6*Q1) Cnode=1E12/(Fo^2*1E12*39.48*L) L=1E9*L C12=K12*Cnode C23=K23*Cnode C1=(Cnode-C12) C2=(Cnode-C12-C23) C3=(Cnode-C23-C23)

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In the schematic, the component values for the inductors and capacitors are replaced by variable names such as C12 which are defined in the Equation window.

The first line in the Equations text assigns the value of 100 to the variable Fo. This variable represents the center frequency in MHz. The question mark following the equal sign tells GENESYS that this value can be tuned, optimized and analyzed in Monte Carlo in the same way as a value in the schematic.

The format for tune, optimization, and Monte Carlo values in the Equations text is:

Variable_Name = ?Value

A value within an expression cannot be tuned, so the statement

VAR=2*?3

is NOT legal, and generates an error message. To get the desired result, use two lines

A=?3 VAR = 2 * A

The next two lines assign 25 MHz to the bandwidth and 120 to the unloaded Q of the inductors. The remaining lines in the Equation text compute component values for this fifth order 0.25 dB ripple Chebyshev bandpass filter with 50 ohm termination. Q1, QN, K12 and K23 define the Chebyshev response.

This is an unusual Equation text example which provides insight into the behavior of this popular UHF bandpass filter. To experiment with this example, load the file "Equation Example.WSP".

Chapter 16: Substrates

Overview

A subtrate is required in GENESYS whenever a physical component is used in a schematic or netlist. Components which require substrates are:

y Coaxial

y Microstrip

y Slabline

y Stripline

y Waveguide

Substrates can also be used to provide metal and substrate characteristic information to EMPOWER by selecting the substrate name in the EMPOWER Layer table.

To add a new substrate:

1. Right-click on the "Substrates" node in the Workspace window.

2. Select "Add Substrate".

To edit an existing substrate:

1. Right-click the desired substrate in the Workspace window.

2. Select "Properties".

See Also: Substrate Properties Dielectric Constant Loss Tangent Metal Thickness Resistivity Surface Roughness Units

Chapter 17: Optimization

Overview

One of the joys of mathematics is finding a solution to a difficult problem via expressions. But we are engineers; the theory, no matter how elegant, is only a start. Practical problems such as standard values and component parasitics may preclude a purely theoretical solution. When only a few variables in a circuit require adjustment, GENESYS tuning is an effective tool. As the number of variables increases, visualization of the multidimensional variable space is difficult, and tuning becomes less effective. In this event, optimization is the preferred tool for dealing with practical problems. A circuit optimization is not "run", but rather "played". Optimization is often a compromise of conflicting requirements with no exact solution. Effective use of optimization consists of an attempt, evaluation of the results, and retries.

GENESYS includes two distinctly different optimization algorithms; a gradient search and a pattern search with adaptive and independent step size for each variable. Eagleware Corporation considers these routines proprietary. However, they are described here in sufficient detail for effective use of the optimizer. Also, it cannot be overemphasized that a major factor contributing to the effectiveness of GENESYS optimization is its unmatched execution speed.

The gradient optimizer is very effective in the early phase of an optimization effort. It is reasonably tolerant even of poor initial component values and a large number of components. It often makes significant progress after only a few rounds. However, gradient search algorithm progress tends to halt before achieving optimum final values.

The GENESYS pattern search is effective in the final phases of an effort. It is based on an optimizer described in the paper, "The Effectiveness of Four Direct Search Optimization Algorithms", Randall W. Rhea, IEEE 1987 MTT-S International Microwave Symposium Digest, June 9, 1987. The current routine improves the previous routine because 1) adaptive and independent variable step size was introduced and 2) fewer evaluations of the

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circuit are required for a given number of steps of the variables. The pattern search algorithm is very resistant to "hang."

GENESYS contains an automatic mode which initially invokes the gradient optimizer. When progress halts as evidenced by a suspension in the decline of the error from target (objective function), the pattern search algorithm is invoked. A fixed number of pattern searches is applied and then the gradient optimizer is again invoked. The user begins this automatic optimization mode by selecting "Optimization/Automatic" from the Actions menu.

See "Antennas\Array Driver.WSP" for an example which uses optimization.

Entering Targets

To enter a set of optimization targets:

1. Right-Click on Optimizations in the Workspace Window and select "Add Optimization Targets."

2. Enter a name for this set of targets and press OK.

3. Enter your targets into the Optimization Targets dialog as shown below. (See the Reference manual for details on this box.)

This optimization block is for an amplifier. It instructs GENESYS to try to make the forward gain (S21) equal to 11 dB and the input and output reflection (S11 and S22) better (less than) -16 dB. The frequency range for all targets is 2100 MHz to 2900 MHz. Also, the Weight of the S21 target is 10, meaning that the

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optimizer will put more importance on that target than on the S11 and S22.

Each target line may specify one or more of the measurements described in the reference manual. The avaiable operators are =, >, < and %. The = operator attempts to optimize to the specified value. < or > attempt to optimize a parameter to be less than or greater than the specified value. The % operator attempts to flatten the specified parameter (the target is ignored with this operator).

This four line set of targets for a bandpass filter:

Measurement Op Target Weight Min Max

S21 < -40 1 10 40

S21 > -1 1 55 85

GD[S21] % 1 100 130

S21 < -40 1 100 130

attempts to achieve at least 40 dB of rejection in lower and upper stopbands and less than 1 dB insertion loss with flat delay in the passband.

This four line optimization block for an amplifier


S21 > 11.5 1 2000 4000

S21 < 12.5 1 2000 4000

S11 < -10 1 2000 4000

S22 < -10 1 2000 4000

attempts to achieve better than 10 dB of return loss in an amplifier with 11.5 to 12.5 dB of gain. A similar optimization block would be


S21 = 12 1 2000 4000

S11 < -10 1 2000 4000

S22 < -10 1 2000 4000

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TIP: To reduce optimization time, specify a minimum number of frequency points.

CAUTION: It is very important that the frequencies at which the circuit is optimized are also frequencies included in the simulations. Optimization will not create any new simulation frequencies.

Starting Optimization

Once you have entered your optimization targets, you start the optimization by selecting an Optimize item from the Actions menu. (The Optimization overview section describes the different optimizer types.) The optimization will run until you press Escape. During the run, you may manipulate graphs, change optimization weights, and make other minor changes to your workspace. Major actions, like saving values or loading a new workspace, cannot be done until you stop the optimization.

When optimization runs, it will optimize all targets in all sets of all loaded workspaces. To disable targets temporarily, set their weight to zero.

Objective Function

Each set of component values results in an error from the desired response. The error computed by SuperStar is the root mean square of individual parameter error terms. The error per frequency is given by

where

p = error function power (always 2 or 6) Tn = Set of target values An = Set of actual values Wn = Set of target weights

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The exponent "p" is always even, therefore the magnitude of each error contribution is always positive. When the user selects pattern search, p=2, which results in a root-mean-squared error minimization. When the user selects gradient or automatic optimization, p=6, which tends to a Chebyshev error minimization.

Each target adds to the error value as determined by the above equation. The total error value is the sum of the errors per frequency divided by the number of frequencies, these added for each target. A specified parameter has a default weight of 1 unless modified by the weight option.

The optimization routine attempts to reduce the total error value by adjusting the values of all components in the circuit file or schematic marked with a "?".

The error and number of rounds are displayed on the status bar at the bottom of the screen during the optimization process. Each round evaluates all marked components.

If the user selects gradient optimization or the automatic mode from the menu or the automatic mode, optimization begins immediately. Optimization continues until interrupted by pressing Esc or until the error reaches zero. Optimization may be interrupted and restarted at will. Manual tuning may be applied during the interruption.

If the user selects pattern search optimization, the variable step size is prompted and optimization begins. For broadband circuits, a moderate step size such as 5% is reasonable. For narrow-band circuits a smaller initial step size is recommended. Because the step size is adjusted dynamically during optimization, the initial step size is not critical.

After optimization has run a while, variable step sizes normally decrease. If optimization is interrupted to manually adjust variables, it is good practice to specify a smaller step size when restarting optimization.

If too large an initial step size is chosen, the early rounds of optimization do not modify the circuit values; they are used to reduce the variable step sizes. On occasion, the error value may actually increase. This attribute of GENESYS optimization allows it to "wander" in search of a better ultimate solution. If this happens at the beginning of a run, it may be indicative of too large an initial step size.

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A powerful feature of GENESYS is the ability to observe results, interrupt the run and manually tune one or more variables, and restart the optimization process. This adds considerable power and flexibility to the routine.

Weights

Any optimization parameters may include weights. When a target is specified, the weight defaults to 1. Use a weight factor greater than one (such as 10) to make the target more important. Use a weight factor between zero and one (such as 0.1) to make the target less important.

For many optimizations, weight factors are unnecessary. This is often the case when the specified parameters are similar in value. Use of < and > operators instead of = also reduces the need for weights. When the error resulting from a parameter is zero because the condition is satisfied, the weight multiplier has no effect.

When the optimized parameters represent a wide range of values, weights are used to obtain a more desirable solution. Remember, optimization is a search for a compromise. Weights are not used to obtain a "correct" solution, but rather to "sculpt" a solution more desirable to the user. This is why we say optimization is not run but played. The user observes the optimization results and then modifies the parameter targets and weights to obtain a "better" solution.

Chapter 18: Yield/Statistics

Overview

Experienced RF/microwave engineers know that capacitors are not capacitors and inductors are not inductors. The parasitics associated with a component can significantly affect the circuit response. Skilled designers include appropriate parasitics in the circuit description. Because lumped-component parasitics are strongly influenced by the implementation, such as component mounting, expecting the circuit simulator to handle all the parasitic issues is unrealistic. The engineer who studies the components and models his or her circuit carefully will acheive a level of performance and agreement that others don't even comprehend.

Production oriented design involves an additional step. The effects of component tolerances on responses encountered in the production process is studied to gain confidence that the yield will fall within acceptable limits.

One method of gaining confidence is to consider worst case scenarios. The circuit response is computed with each component stepped up or down in value by the appropriate tolerances. The response is observed while all components are stepped in the direction resulting in the worst possible outcome for the parameter being considered. This process is fast and insightful with a real-time simulator such as GENESYS. However, the outcome is generally pessimistic. Redesign, to fit worse case scenarios into desired specifications, may result in greater cost than rejecting or repairing a few units which fail test.

Monte Carlo analysis evaluates circuit behavior for a sample run size with a random distribution of component values within specified limits. It is a statistical process. It does not tell us with certainty what will happen with a particular unit, but it gives us confidence that production results will fall within acceptable limits.

Entering Targets

Yield Targets are identical Optimization Targets, except the "=" and "%" operators are almost never used because the yield

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would be zero (the measurements will almost never be exactly equal to the targets). The ">" and "<" operators are used to specify the range of output parameters which constitute a successful unit. The Optimization Targets are used to find component values which result in the desired nominal responses. The Yield Targets are used to set acceptable limits for definition of what is a successful unit during Monte Carlo analysis. See Entering Targets in the optimization section for the exact steps for entering targets. An example amplifier Yield Target Set might be:


S21 > 11.5 1 50 950

S21 < 12.5 1 50 950

S11 < -10 1 50 950

S22 < -10 1 50 950

This specifies that all trials with a gain between 11.5 and 12.5 dB, and with better than 10 dB return losses, are considered to successful.

When the workspace includes yield targets, the number and percentage of passes which meet the targets are displayed during a Monte Carlo run. If a yield targets do not exist in the workspace, the Monte Carlo paint occurs, but the error is computed as zero and the yield is 100%.

The rules and options for use in the yield targets are nearly identical to optimization targets. Although the rules and options are identical, the philosophy for using the optimization block are different for Monte Carlo analysis and circuit optimization. If the above goals were used to optimize the amplifier, the response would likely be close to either 11.5 or 12.5 dB, at least at some frequencies. Using this same block in Monte Carlo would then result in a poor yield. Instead, using these targets for circuit optimization:


S21 = 12 1 50 950

S11 < -16 1 50 950

S22 < -16 1 50 950

would tend to center the gain response at 12 dB. Then, using yield targets for Monte Carlo with limits of 11.5 to 12.5 dB would produce a better yield.

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The error value reported during optimization, tuning and Monte Carlo are all computed by the same algorithm.

Variable Setup

See the Dialog Boxes section of the reference manual for details on the Statistics Setup Dialog for setting component tolerances and distributions.

Monte Carlo Example

The figure below shows two 7th order 0.0432 ripple Chebyshev filters designed in FILTER and merged together in workspace file MONTE.WSP. The filter on the top is a top-C coupled bandpass from 850 to 950 MHz and the bottom filter is a lowpass with a cutoff of 900 MHz.

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The responses with nominal element values are shown below. The 0.0432 dB passband ripple results in approximately 20 dB return loss in the passband. During synthesis in FILTER, the capacitor Q was set to 600 and the inductor Q was set to 130 for both filters. Notice that the insertion loss due to finite component Q is greater in the bandpass than the lowpass.

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The two filters were merged together by pasting the entire schematic of the bandpass into a new schematic in the workspace written from FILTER for the lowpass. Next, all the parts are selected by drawing a box around them and then from the Schematic menu, "Make Tunable..." is selected. This places a question mark with the first value of every component in the schematic. Question marks preceding component values in the file indicate those values are included in the Monte Carlo analysis.

Next, from the Actions menu, "Setup Variables" is selected. The Statistics Setup window is shown. Distribution type and tolerances are entered for all components. Alternatively, all

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components can be set at a specified distribution and tolerance. All options are discussed in the reference manual. In this example all components are left at the default ±5% uniform distribution.

Next, from the Actions menu "Monte Carlo" is selected. Monte Carlo paints multiple responses on the screen, each with a psuedo-random set of component values based on the specified distribution and tolerances. The process continues until the specified number of runs (sample size) is achieved. Results are shown below. At the end of the run, the markers display response values for the nominal component values.

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Even though these filters were designed from the same lowpass prototype and the component tolerance for both are ±5%, notice that the sensitivity of the bandpass is far greater than the lowpass. The worst return loss case for the lowpass is approximately 13 dB while several of the bandpass samples have a return loss of only 3 dB! Such outcomes might not be intuitively obvious prior to Monte Carlo analysis. Monte Carlo analysis can be very insightful and provides an understanding of circuit behavior and problem areas.

Worst Case vs. Monte Carlo

Shown on the left in the figure below is the response of the lowpass filter used in the example above with all seven components stepped 5% in the direction resulting in the poorest return loss near the cutoff frequency. Given on the right is the response with the worse set of 5% stepped values resulting in the greatest shift in the cutoff frequency.

These conditions were found by manually tuning element values while observing the responses. Different worse case scenarios, such as return loss at low frequencies, require a different set of component values. Results are poorer than the worst response encountered during the Monte Carlo run shown This is typical of the differences between worse case and Monte Carlo analysis. As the number of components affecting the response increases, it becomes unlikely that a run will exist where all values fall at extreme values in the direction causing the worst response. However, when only a few components affect the response, Monte Carlo is more likely to produce a near worse case run. Also, if one component exhibits the greatest sensitivity, a near worse case run is more probable.

When a number of response specifications exist, more than one set of worse case component values may exist. The set of component directions are typically different for different response specifications. Although Monte Carlo may not find worst case responses, the user is relieved of the tedium of manually tuning several sets of worst case component values.

Sensitivity Analysis

Selecting "Sensitivity" from the Statistics menu displays sensitivity plots in sequence for each variable in the Tune Window. Display pauses for viewing for each variable until the

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user strikes the Enter key. In each sensitivity plot, the responses are displayed with components at the nominal and specified deviation up and down values. The deviation values are the limits for uniform distribution, and the one-sigma values for normal distribution.

Sensitivity analysis is useful for characterizing and identifying individual relationships between components and the circuit responses. It is yet another tool to assist the designer with understanding circuit behavior and managing production yield.

Design Centering

Optimization finds specific component values which provide the best flatness, return loss, etc. However, when components assume a range of values due to tolerances, the optimized nominal values may not be the best values from a yield perspective, particularly if the objective function errors are different for equal component steps up and down in value.

Design centering is a process which attempts to maximize yield by adjusting the nominal component values so the objective function errors are equalized. Design centering is more likely to increase yield if component tolerances are loose.

Consider the example Chebyshev lowpass filter in the previous example. The Monte Carlo run shown resulted in a yield of 52%. (There was no yield block for the bandpass so it was not included in yield calculations.) From the Actions menu, "Design Centering" was selected. After 10 runs of design centering, the yield was improved to 72%.

You may find the following remarks helpful for Design Centering:

y Optimize completely before Design Centering.

y When testing a centered design, use Monte Carlo sample sizes > 200.

y Monte Carlo and Design Centering are statistical. Runs with different seeds vary significantly. Don't expect exact yield prediction.

y Design Centering is a fine adjustment. Precise circuit modeling is required. Include all possible component parasitics before proceeding.

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Yield Optimization

Yield Optimization was a new feature in Version 6 of GENESYS. Yield Optimization is typically far more effective and its use is now recommended over Design Centering.

Yield Optimization finds element values based on the following equality:

where

Vj = the new value of the jth tunable variable. Vj,m = the jth tunable variable value at successful sample m n = number of samples where the yield is successful.

The principle of Yield Optimization is simple. It simply averages the element values for all the samples which satisfy the yield conditions. This simple principle is the most effective technique we have found for improving yield.

To lauch Yield Optimization from the Actions menu select Yield Optimization. Next, enter the depth of search. "1" confines the search to a narrow spread of element values around the nominal values. It results in a fast solution, but the best yield may not be found. "5" is the slowest option and searches over a wider spread of element values. Fewer samples result in a succesful yield and progress is slowed. However, improved yield is likely because element values are averaged over the widest possible range of values which result in success. During a Yield Optimization, if the output display "sample hits" is usually zero, select a lower depth of search.

You may recall that the original yield of the lowpass filter example was 52%. Design Centering improved the yield to 72%. On a 75 MHz Pentium machine, Yield Optimization with the Fastest option resulted in a 80% yield within 8 seconds, the Medium option achieved a 96% yield in 17 seconds and the Slowest option achieved a 100% yield in 50 seconds.

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Monte Carlo Report

Selecting Write Monte Carlo Report from the Actions Menu causes Monte Carlo to generate an ASCII text file containing a detailed description of the run. For each sample an entry is included with component values and the resulting error. This file can be lengthy but it identifies component value sets which result in poor performance. Excerpts from such a text file are given in below.

Monte Carlo Report for C:\newex\monte.wsp, Fri Sep 17 16:40:03 1999

Number of Samples: 51 Seed: -65536

Nominal Values: C,C1: 3.5647 L,L1: 12.704 C,C2: 6.8606 L,L2: 14.341 C,C3: 6.8606 L,L3: 12.704 C,C4: 3.5647

Round 1 C,C1: 3.57539 L,L1: 12.8021 C,C2: 6.99423 L,L2: 14.4171 C,C3: 7.12034 L,L3: 12.1955 C,C4: 3.617 Yield Error: 1.16699 FAILED ... Round 50 C,C1: 3.45593 L,L1: 12.4992 C,C2: 6.70398 L,L2: 14.1204 C,C3: 6.58675 L,L3: 12.8415 C,C4: 3.44191 Yield Error: 0 PASSED

Final Yield: 33 of 50 (66.00%)

Chapter 19: Entering Notes

Overview

The notes window give you a place to document your designs and make observations. As with all other items on the workspace tree, these notes are stored with the workspace. The notes window works similarly to Windows' Notepad program. Some common things to do with the notes window include:

y Print the contents (Select Print from the File Menu)

y Cut/copy/paste the text to a word processor for documentation.

y Leave a documentation trail to help co-workers understand your designs.

Chapter 20: Exporting Files

Overview

Eagleware programs can write many types of files. These files include:

y S-Parameters

y EMPOWER data files

y DXF Files

y Gerber Files

y HPGL Files

y ASCII Drill Lists

y Excellon (Gerber) Drill Lists

y SPICE Files

y Touchstone Files

S-Parameter files are discussed in the Device Data section of the Reference manual. The export of EMPOWER data files is discussed in your EMPOWER manual. DXF Files, Gerber Files, HPGL Files, ASCII Drill Lists, and Excellon Drill Lists are discussed in the Export Dialogs section of the Reference Manual.

The remaining two types of files are SPICE and Touchstone. These export formats allow users to run SPICE and/or Touchstone circuit simulations from their Eagleware files. Touchstone circuit files are similar to SuperStar netlists and are generally a one-to-one translation. A Touchstone file can also be exported from an Eagleware synthesis program via its Export menu. Exporting a SPICE circuit file requires some setup and is initiated from SCHEMAX. A limited equation translation capability has been incorporated.

Note: If you will be exporting a SPICE file, be sure that "Show SPICE details in part dialogs" is checked in the SCHEMAX Global Options tab (select Options from the Tools menu).

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Exporting to Spice

Exporting SPICE files is performed from SCHEMAX. This is because many SPICE device models are significantly different than linear simulator models. Terminations are often handled differently in SPICE and linear simulators. In SuperStar, oscillators are analyzed open loop while the loop is closed for SPICE analysis. These differences are resolved in SCHEMAX.

Because of variations in SPICE formats, many of these resolutions are handled manually. Back loading (annotation) is not supported; any changes made to an exported SPICE file cannot be loaded back into SCHEMAX.

When Export SPICE file is selected, the SPICE Preferences dialog box is shown. Details on this dialog box are in the Reference manual.

How Parts Translate to SPICE

There are three categories of part translation to SPICE: Direct, Incompatible, and Compound. For translations for specific parts, see Circuit Elements in the Reference Manual.

Direct parts are translated on a one-to-one basis. Examples include CAP, IND, RES, Signal Ground (Voltage Source), TLE, TLE4, TLP, and TLP4. Incompatible parts are those that have no simple SPICE equivalent, including physical models, S- or Y-parameter devices, and internal transistor models (FET and BIP).

Compound parts are parts that are translated as SPICE subcircuits. They include MUI, OPA, VCC, and XTL. This provides comparable simulations in SuperStar and SPICE. For example, an Eagleware VCC is modeled by two resistors and a voltage controlled current source. To use just the SPICE VCC device without the resistors, you may override the default translation by double-clicking on the VCC device. This presents the Part Details dialog box. Select ‘G’ from the SPICE Device list and click the OK button to save the changes.

Some special notes on Compound parts are:

1. The SPICE opamp E model (SuperStar translates OPA as an ‘E’ model) is ideal in that the unity crossover frequency is infinite. You may substitute a SPICE library model or subcircuit for the opamp. Most opamp manufacturers have SPICE Models for their products.

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2. The SuperStar TRF device (Ideal Transformer) is not supported in SPICE. You should specify an MUI (Mutually coupled inductors). You will need to specify appropriate winding inductance and coupling.

3. The SuperStar FET and BIP devices do not include any biasing information and so are not translated. You may individually specify how to translate these parts by defining the translation device in the Part Details dialog box.

Incompatible Parts are identified in the translated SPICE file with exclamation point (!) at the front of the part line. A SPICE model (.MODEL) or subcircuit may be assigned to that part in the Part Details dialog box. You must also place a SPICE Model definition (.MODEL block) in the exported SPICE file. This is done either through SPICE Command Text or manually after exporting. If the SPICE simulator supports libraries (both PSPICE and IsSPICE support libraries), the library reference is included in SPICE Command Text entries

Example: Spice Export.WSP

This example uses a file (Q2N6618.TXT) from the Intusoft RF Library (RF.LIB, © 1995, Intusoft). The library is a high quality collection of RF devices and is available for use with their IsSPICE simulator. This lib rary makes IsSPICE an ideal choice for RF SPICE simulations.

This is a 125 MHz bipolar oscillator created in =OSCILLATOR= using a 2N6618 bipolar NPN transistor (10V/3mA). This transistor is modeled in SuperStar by a TWO device (S-parameter data file 2N6618A.S2P). A SPICE model for the transistor has been included in the example directory as Q2N6618.TXT. (See the note above.)

The SuperStar open-loop analysis indicates sufficient loop gain for oscillation and the phase zero crossing (oscillation frequency) occurs at approximately 128 MHz. The book Oscillator Design and Computer Simulation discusses oscillator design in detail, including additional oscillator simulations using SPICE.

In this SPICE example we will:

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1. Model a TWO device with a SPICE transistor library model.

2. Setup a transient analysis of the oscillator circuit.

3. Add a model reference in SPICE Command Text.

Once the file is loaded, select SPICE Preferences from the Export menu. The Primary Circuit selection should be LOOP. Choose the Target Version; this example is targeted for IsSPICE. Terminations is set to Closed Loop. The Closed Loop setting causes Export to connect the input node directly to the output node via a 0 Volt power source in the resulting SPICE file. This simply serves as a zero ohm connecting element. Select OK to continue.

In =OSCILLATOR=, a TWO device was used to input S-parameter data to model the transistor. In SPICE a model or subcircuit must be used for this part. Transistor models and libraries are available from part manufacturers and SPICE software developers.

To specify a library model, the Part Details dialog box for the transistor is opened from the schematic by selecting the part and pressing F4 or by double clicking the part. Select “X Subcircuit” as the device type in the Device list box under SPICE Information. Next, specify the subcircuit name (Q2N6618) in the Parameters field. The Output field then displays the SPICE text line that is generated when the file is Exported.

The subcircuit must use the same number of nodes as your part. In this case, the TWO part has three nodes and the subcircuit (Q2N6618.TXT) has three nodes.

Next we proceed to the SPICE Command Text to setup the transient analysis and add the transistor subcircuit definition. The SPICE Command Text edit window should be:

* Target Version for this Example is IsSPICE v4.0 * This example was tested in IsSPICE v4.0 and PSPICE v6. * .TRAN performs a Transient Analysis to 2000 nS. * .PRINT outputs the Transient Voltage at the output node. .TRAN 2N 2000N UIC .PRINT TRAN V(6) * To use the 2N6618 Transistor .SUB file: * For SPICE2 and SPICE 3, Copy text from * file Q2N6618.TXT to here

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* The next line includes the file for IsSPICE *Include Q2N6618.TXT ;Change the * to a . for PSPICE

The transient line (.TRAN) requests a circuit transient analysis (oscillator starting waveform). This is resource intensive and requires significant processor power and system memory. SPICE simulator requirements vary. Please check your SPICE documentation for running requirements. For example, this simulation in PSPICE with the .PROBE command requires about 14MB of hard disk space and 3 minutes on a Pentium class machine.

The UIC parameter tells SPICE to Use Initial Conditions. This facilitates starting. Alternatively, UIC may be omitted and the supply specified as pulsing on at t=0. The .PRINT command causes SPICE to print the transient voltage at the output node (node 6).

The next section of the text involves the subcircuit line “X1_2N6618 6 30Q2N6618". The specific format for including the subcircuit data for the 2N6618 transistor is SPICE version dependent. PSPICE uses a SPICE Dot Command (.INCLUDE) and IsSPICE uses either a SPICE Dot Command (.INCLUDE) or a special comment format (*INCLUDE). The file Q2N6618.TXT contains the subcircuit definition for the 2N6618 NPN transistor. If your SPICE simulator does not support file inclusions, then you can simply cut and paste the text from the data file into the SPICE Command Text window. In this example, the IsSPICE *INCLUDE was used.

Select Export SPICE File from Export in the File menu. Choose the name SPICE3.CIR. An IsSPICE transient analysis graphical output screen is given below. Oscillation starts in approximately 30 nS and builds to 4 volts peak-to-peak. The oscillation frequency determined from the time period agrees with the SuperStar analysis.

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Chapter 21: Using Files from Earlier GENESYS Versions

Using Files From Earlier GENESYS Versions

GENESYS imports files created with SuperStar Version 4 or later. The following features from old files will not be imported by GENESYS:

y Post Processing - GENESYS now has better post processing capability, and is not compatible with the old technique. For information on the new post processing procedure, see the Reference manual. Also, see the example file "Model Extract.WSP".

y 3D Graphs - Parameter sweeps are now different from old versions, so 3D graphs will have to be recreated after importing. See: 3D Graphs, Parameter Sweeps.

y EMPOWER Simulation Data - EMPOWER calaculated data is now stored inside the workspace file, instead of separate files. Simply re-calculate the data after importing. Also, you may want to re-setup any decomposition examples, as there are easier ways to setup these files in Version 7. See your EMPOWER manual for details.

y Multiple Impedances - Files with multiple WINDOW blocks reusing the same network to simulate different terminations will only use the first set of terminations. Impedances are now stored in the ports and can also be tuned. If you still need multiple impedances:

1. Load your schematic.

2. Create other schematics using NET blocks to reuse the schematic loaded in (1) to use all desired terminations.

y Radial Stubs (MRS) - There is a new radial stub model in GENESYS 7 with only one port. You will need to replace any radial stubs with a microstrip tee plus the new stub. See Radial Stub (MRS) in the Elements section of the Reference manual.

Chapter 22: Keyboard Commands

General Keystroke Commands

Note: Availability depends on active workspace window

y Space to place another copy of the most recently placed item

y Escape to cancel current mode

y Delete Delete current selection

y Ctrl+A Select All

y Ctrl+C Copy

y Ctrl+D Duplicate

y Ctrl+N File New

y Ctrl+Shift+N Select None

y Ctrl+O File Open

y Ctrl+P Print

y Ctrl+V Paste

y X zooms to mouse rectangle

y Ctrl+X Cut

y Ctrl+Y Redo

y Z zoom to fit

y Ctrl+Z Undo

y Ctrl+Shift+Z Redo

y Shift+Z for zoom to fit with extra margin

y + zooms in

y – zooms out

y Ctrl+End for zoom to page / 0 db scale (maximize)

y Ctrl+Home for zoom to fit

y Ctrl+PageUp for zoom in

y Ctrl+PageDown for zoom out

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y LeftArrow , RightArrow , UpArrow , and DownArrow moves the current selection

y Ctrl+LeftArrow , Ctrl+RightArrow , Ctrl+UpArrow , and Ctrl+DownArrow scrolls the view

y F3 rotates an item clockwise

y Shift+F3 rotates an item counter-clockwise

y F4 to bring up Element Properties

y F6 mirrors an item

y Alt+F7 print/export entire Genesys application window

y F8 next editor

y Alt+F8 print/export entire active window

y F9 show all output windows, again to advance to next output window

Graph Output Keystroke Commands

y Tab selects the next marker

y LeftArrow , RightArrow , UpArrow , and DownArrow moves current marker

y Ctrl+LeftArrow , Ctrl+RightArrow , Ctrl+UpArrow , and Ctrl+DownArrow scrolls a Smith chart

=LAYOUT= Keystroke Commands

y F Flip selected line or arc

y G Group

y D Redraw

y O Toggle orthogonal line mode

y P Pour

y R Toggle rounded (pads or lines)

y U Ungroup

y F11 Show Layout Preferences

SCHEMAX Keystroke Commands

y Enter to bring up Element Properties or to exit arrow-key "move selection" mode (if active)

y A to place an Ammeter (CURRENT_PROBE)

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y B for BLOCK (two port)

y C for CAPACITOR

y D for DIODE

y G for GROUND

y I for INPUT port

y L for INDUCTOR

y M for MLI_SLI

y N for BIP_NPN

y O for OUTPUT port

y P for BIP_PNP

y Q for SQUARE_BLOCK

y R for RESISTOR

y S for SIGNAL_GROUND

y T for TEXT (left justified)

y V for Voltage TEST_POINT

y W for 90 degree WIRES (Shift+W for any angle wires)

y X zooms to mouse rect

y Y for CRYSTAL

y Z zooms to show all parts

y 1, 2, 3, …, 0 places 1-Port, 2-Port, …, 10-Port

y Shift+B for MLI_BEND

y Shift+C for MIDCAP

y Shift+E for TRL_END

y Shift+G for TRL_GAP

y Shift+L for MSPIND

y Shift+M for MLI_SLI

y Shift+R for RADIAL_STUB2

y Shift+S for TRL_STEP

y Shift+T for TRL_TEE

y Shift+V for TRL_VIA_SMALL

y Shift+W for angled WIRE

y Shift+X for MLI_CROSS

y Shift+Z for zoom to show all parts (with extra margin)

y Shift+1 for MLI_SLI

Keyboard Commands

186

y Shift+2 , Shift+3 , …, Shift+0 places 2-LINES microstrip, 3-LINES microstrip, …, 10-LINES microstrip

Index

3 3D, 112, 136, 142

A Absolute Error , 113 Absolute Tolerance , 129 AC, 112 Actions Menu , 165 Add Optimization Targets ,

158 Add Substrate , 155 Adding , 34

Comment Text , 34 Admittance , 144 Ammeter , 116, 120 Amplitude Stepping , 130 Annotate , 116, 120 Annotation Objects , 139 Arcs , 57 Artificial intelligence

techniques , 130 ASCII Drill List , 175 Assembly , 79, 92, 100 Association table , 72, 73, 77 Associations , 39, 73 Automatic deembedding , 107 Automatically Calculate , 114 Automatically Connecting

Layout Objects , 64 Available Footprints , 93

B Bandpass Filter With

Equations , 151 Berkeley , 86 Bottom Mask , 79, 92 Bottom Silk , 92 Box , 107 Box Modes , 107 Bridge-T , 22

C Calaculated data , 181 Capacitors , 163 Change Footprint , 73 Changing , 34, 36

Model , 36 orientation , 34

Characteristics , 107 Chebyshev , 160 Chebyshev lowpass , 170 Circles , 19, 139 Circles/squares/triangles ,

136 Closed Loop , 176 Combo-box , 36 Comment Text , 34 Component Object , 70 Components , 32, 39, 55, 72,

73, 76, 77, 81, 91, 92, 93, 95, 96, 163, 170

Compression , 124, 128 Compromise , 162 Connect Selected Parts , 64 Connections , 32, 36, 57, 79,

94, 100 Connectors , 55, 70 Convergence , 113, 129, 130 Coupled lines , 74 Create Mask , 67, 68 Creating , 22, 145

Polar Chart , 145 Schematic , 22

Cut , 63 Cutout button , 82

D Data, 107 Data File , 19, 111 DBm operator , 128 DC, 112 DC Analysis , 116, 120 DC Analysis Overview , 112 DC biasing , 107

Index

188

DC Current , 116 DC Curves , 116, 120 DC Voltage , 116 Default Text Font , 65 DEFAULT.EWF , 65 DEFAULT.MOD file , 47 Default.WSP , 19 Delete This Simulation/Data ,

114 Deleting , 32, 60

Elements , 32 Objects , 60

Design Centering , 170, 171 Design Manager , 21 Designs , 11, 21, 22, 55 Discontinuities , 74 Discretizes metal , 107 Distortion , 128 Distribution , 107, 163, 165 Documentation , 36, 173 Draw Size , 100 Drill Diameter , 100 Drill List , 175 DXF File, 175

E Eagleware , 107 Electromagnetic , 107 Electromagnetic simulation ,

107, 111 Elements , 31, 32, 34, 39, 47,

55, 74 Deleting , 32 Mirroring , 34 Selecting , 31

EMPOWER, 55, 107, 111, 181 Equation Example.WSP , 151 Equations , 19, 39, 41, 107,

147, 151 EURO.EWF, 65 Excellon , 175 Export menu , 175 Exporting , 176

Spice , 176

F Fast Newton , 129, 130 Filter.WSP , 19 Fonts , 65 Footprint Editor , 91, 92, 93,

94, 95, 97, 100 Footprint Example , 97 Footprints , 55, 72, 73, 74, 76,

77, 92, 94, 95, 96 FOUR.LYR, 79 Full Jacobian , 130

G Gap, 74 General Layer , 81 Gerber , 65, 82, 83, 175 Global Options , 32 GOTH.EWF, 65 Graph Properties , 141 Graph Properties dialog , 27 Graphs , 139, 181

Annotating , 139 Grid , 32 Ground Plane , 55, 67, 68, 79,

83, 84, 107 Group , 76 Group Object , 64

H Handles , 61 HARBEC , 86, 113, 124 HARBEC Options , 129, 130 HARBEC Popup Menu , 114 Harmonic Balance , 113, 129,

130 Hiding , 80

Layers , 80 HPGL file , 175 HPLIB.LIB , 91, 96

I Ideal Transformer , 176 Impedances , 35, 144, 181 Intermodulation , 128

Index

189

Intusoft , 176 IsSPICE, 176

J Jacobian , 129, 130

K Keep Away , 67, 68, 83, 84 Keystroke Commands , 183 Krylov , 130

L Layer File , 81 Layer Table , 79 Layers , 80

Hiding , 80 LAYOUT , 55 Layout Menu , 73 LCOM.EWF, 65 LEADED.LIB , 91, 96 LF347, 100 Library , 70, 72, 81, 91, 93, 95,

96 Line Object , 97 Line Width , 97 Linear Simulation , 107, 111,

122, 124 Lines , 57 Link , 19, 111 LITT.EWF, 65 Load From Layer File , 81 Loop Oscillator.WSP , 19 Lumped-component

parasitics , 163 LYR Files , 81

M M/FILTER, 64 Main GENESYS Window , 7 Make Tunable , 15, 165 Manufacturers , 128 Markers , 136 Mask, 79

Maximize button , 138 Maximum Amplitude Step ,

130 Maximum Mixing Order , 130 MBN, 74 MCN, 74 MCP, 74 MCR, 74 MCURVE, 74 Measurements , 128, 133, 145,

158 MEN, 74 MESFET's, 86 Metal , 68, 70, 79, 92, 97 MGA, 74 Microstrip , 35, 74, 107, 181 Microstrip Cross , 74 Microstrip Radial Stub , 74 MIDCAP, 74 Minimization , 160 Mirror , 67, 92 Mirrored Layers , 81 Mirroring , 34

Elements , 34 MIXER, 36 MLI, 74 Model , 19, 36, 39, 41, 47, 89,

128, 181 Changing , 36

Model Editor , 47 Model Extract.WSP , 19 Monte Carlo , 151, 163, 165,

169, 170 YIELD Block , 163

Monte Carlo Report , 172 Moving , 61

Objects , 61 Moving Elements , 32 MRIND, 74 MRS, 74 MSPIND, 74 MST, 74 MTAPER, 74 MTE, 74 MU, 19 Multi-Device Footprints , 77 Multiplier , 162 MVH, 74

Index

190

N Narrow-band , 160 Neg R Oscillator.WSP , 19 NET, 36 Netlist , 49, 50, 52 Netlists , 53, 175 New Footprint , 93 Newton-Raphson , 130 Non-linear , 107, 112 Nonlinear Device Models , 85,

128 Nonlinear JFET , 86 Nonlinear MESFET

Transistors , 86 Nonlinear MOSFETs , 86 Non-standard metal , 107 Normal Distribution , 169 Notes , 173

O Object Handles , 61 Objective Function , 157, 160,

170 Objects , 61, 62

Moving , 61 Op-amp , 72, 77, 95, 100 Operational amplifiers , 34, 96 Operations , 32 Operators , 128, 158, 162 Opt/Yield/Recalc , 114 Optimization , 19, 157, 158,

160, 162, 163, 170, 171 Starting , 160

Optimization Targets , 19, 160, 163

Optimizing Simulation Performance , 130

Orientation , 34 changing , 34

Output , 11, 100, 135, 136, 145, 148

Outputs Manager , 136 Overview , 55

P Pad Height , 97 Pad Shape , 94, 97 Pad Width , 97 Pads , 62, 67 Page Down , 15 Page Up, 15 Parameter Sweep , 112, 116,

124, 129, 181 Parameters , 39, 62, 181 Parasitics , 107, 157, 163, 170 Passband , 19 Paste, 63, 79, 92 Percentage , 15, 16 Phase Noise , 107 Planar 3D Electromagnetic

Simulation , 111 Polar Charts , 136, 138, 145 Polygons , 82 Port Number , 95, 100 Ports , 35, 62, 181 Post-processing , 19 Pours , 83, 84, 107 Power And Ground

Connections , 79 Prediction , 170 Pressing , 160

Esc , 160 Property Dialogs , 62, 136 PSPICE, 176

R Recalculate Now , 114 Recalculation button , 114 Rectangles , 57 Rectangular Graph , 136, 141 Reference , 62, 181 Relative Error , 113 Relative Tolerance , 129 Rename Footprint , 94 Replace Part With Open , 60 Replace Part With Short , 60 Resistor packs , 77 Resolution , 83 Root-mean-squared , 160 Rotate , 34, 61

Index

191

Round , 67, 68 Rounded Ends , 57 Rubber Bands , 55, 70, 71, 74,

76, 79 Rubber-bands , 100

S S Parameters , 19 SAMPLE.LIB , 91, 96 SANS.EWF, 65 SBN, 74 Schematic , 21, 22, 27, 36

Creating , 22 Simulating , 27

SCHEMAX, 36 SCN, 74 SCP, 74 SCRI.EWF, 65 Segments , 83 Select All , 58 Selecting , 31, 58

Elements , 31 SEN, 74 Sensitivity , 165, 169 Sensitivity Analysis , 169 Setup Variables , 165 SGA, 74 Show Data Points on New

Graphs , 136 Show SPICE Details , 175 Shunt-C Coupled Netlist

Example , 50 Silk , 70, 79, 92, 97 Simplify , 107 Simulating , 27

Schematic , 27 Simulation , 32, 55, 111 Simulation/Data , 111 Simulations/Data , 11, 107 Single Part model , 89 SLI, 74 SM782.LIB, 72, 91, 96 Smith Chart , 19, 136, 138,

144, 145 Solder Paste , 79 SPICE, 85, 107, 175, 176

Exporting , 176

SPICE File Compatibility , 86 Square/rectangular , 67 SSP, 74 Stability.WSP , 19 Starting , 160

Optimization , 160 Statistical , 170 Statistics , 76 Statistics Window , 76 STE, 74 Stopband , 19 Stripline , 35 Stripline Bend , 74 Stripline gap , 74 Stripline Open End , 74 Stripline Step , 74 Sub Above , 92 Sub Below , 92 Substrate , 11, 35, 52, 79, 155 SuperStar , 55, 107, 181 Sweep , 142 Switch/Move Parts , 72, 77 Symbol , 36

Changing , 36 Symbol button , 36

T Tables , 148 Target Version , 176 Targets , 157, 158, 160, 162,

163 Entering , 158, 163

TBL file , 73 Tee, 181 Template , 19 Terminations , 35, 176, 181 Texas Instruments LF347 ,

100 Text , 62, 100 Text button , 34 Text Model Definitions , 47 Text Object , 65 Third-order Intercept , 128 To Group , 76 Tolerance , 163 Tolerances , 165, 170 Tools Menu , 93

Index

192

Top Mask , 92 Top Metal , 92 Top Silk , 92, 100 Touchstone , 175 Transient Analysis , 176 Transistor , 34, 116

DC curves , 116 Transmission Line

Generation , 74 Transmission lines , 107 TRIP.EWF, 65 TrueType fonts , 65 TSCR.EWF, 65 Tune Window , 15, 16 Tuned Values , 16

Reverting , 16

U Undersampled , 129 Ungroup , 64 Uniform Distribution , 165,

169 Units , 53, 97 Untuned , 16 Update Dashed Traces , 17 Up-to-date , 114 Use Default Layers , 68 Use Default Size , 65, 100 Use Previous Solution As

Starting Point , 129 User Functions , 107 User Ground , 67, 68, 84 User Model Example , 41 Using Files From Earlier

GENESYS Versions , 181 Using Substrates , 35

V Variable Setup , 165 Variables , 15, 17, 147 Vendor-supplied models , 107 Version , 181 Viahole , 74 Viaholes , 62, 68, 71 View S Data.WSP , 19 View Variables , 147, 151

W Wagon Wheel , 67, 68, 96 Waveguide , 35, 107 Weights , 158, 160, 162, 163 Widths , 57 WINDOW, 181 Workspace Window , 11, 183 Workspaces , 27, 160, 181,

183 Worst Case , 169 Write Monte Carlo Report ,

172

Y Y-Axis , 141 Yield , 11, 163, 169, 170, 172 Yield Optimization , 171 Yield Targets , 163

Z Zoom , 138 Zoom To Rectangle button ,

31 Zooming/Panning , 33

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