hp-ads tutorial 2015

Jan 26, 2015ECE6360 – Spring ‘15 Microwave Design1/32

Agilent Advanced Design Systems

(ADS) Tutorial

ECE6360 Microwave Design

2015 SPRING


Outline

�Create project

�Schematic window

�Palette

� Microstrip

� S-parameter

�LineCalc

�Simulation

�Optimization

�Variables and equations


Agilent ADS & Momentum

• ADS � Electronic design automation software. Specialized toward high-frequency (RF, microwave) applications. Generally uses empirical equations to evaluate circuit performance.

• Momentum � 3D planar electromagnetic simulator. Explicitly solves for electric and magnetic fields to determine layout/circuit performance.


Create New Project

From the Advanced Design

System (Main) File Menu go

to “New Project”. Enter a

name for your project

directory and click OK. The

schematic window will open.


Schematic Window

Most of what you need can be

found in the TLines-Microstrip

palette, Simulation-S-Parameter

palette (Palettes are the pull-down

menus to the left of the schematic

window. The first one you see is

the Lumped Elements palette.)


TLines-Microstrip Palette

For Duriod example use the

following: H=50 mils, Er=6.15,

Mur=1, cond=1.0E+50, 3.9E+34,

T=1mil, TanD=0.0025


Simulation S-Parameter Palette

Go to the Simulation-S-Param palette, select

TERM (for terminations) and place 2

terminations in the schematic window. These

will act as your two ports. Select a ground and

place in the schematic window. Connect the

wires and grounds.


LineCalc

E_eff=360deg*(length/lamda)

Starting LineCalc:


Simulation

Save the schematic: Go to Simulate → Simulate or press F7


Optimization

Min is the value that is acceptable over the

specified range (ie –40dB put -40). Max is the

maximum value that is acceptable over the

range. Weight is a factor that will declare the

importance of the optimization (10 is usually a

sufficient value). Range var is the variable that

is being swept


Optimization (cont.)

You do not need to define all the

options. It is best to double click

on the object and select gradient

for optimization type, random is

default.


Variables and Equations


Example (Lumped Element)P225 Example

0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.90.1 1.0

-40

-30

-20

-10

-50

0

freq, GHz

dB

(S(1

,1))

C

C1

C=3.18 pF

L

L1

R=

L=38.8 nH

C

C2

C=0.92 pF

Term

Term1

Z=100 Ohm

Num=1

R

R1

R=200 Ohm

S_Param

SP1

Step=0.01 GHz

Stop=1 GHz

Start=0.1 GHz

S-PARAMETERS


Example (Ideal T-line)Z0=50, ZL=15+j10 at 5 GHz


Example (Microstrip)

Z0=50, ZL=15+j10 at 5 GHz


Example (Optimized)

Z0=50, ZL=15+j10 at 5 GHz


Momentum Tutorial

ECE6360 Microwave Design

2015 SPRING


Design Process

1. Choose design

specs & strategy

2. ADS Schematic 3. ADS Simulate

5. Momentum

Simulate

4. Momentum

Layout

Me

ets

sp

ecs

Doesn’t meet specs,

adjust circuit parameters

Simulate EM

Generally, Momentum

simulation results are more

accurate than regular ADS

results


Generate Layout

Click Generate/Update Layout from Layout tap

Click Ok


Momentum

Momentum window will pop up &

ADS will automatically draw the layout for you


Setup Substrate Parameter

In Momentum window, go to Momentum tap,

and choose ‘Substrate-> Create/Modify’

Define thickness, Permittivity, and Loss tangent

Click Apply


Setup Conductor Parameter

Go to Layout layer tap

Choose “-------” and click Strip ( This will set the

“------” as strip conductor


Setup Conductor Parameter (cont.)

Define thickness ( Make sure unit)

Choose material type conductor(Sigma)

Put 5.8e7 in “REAL”

Click Apply


Define Port

Click Port icon (Red circle)

Then you can define port by clicking light blue dot

After define port1,2, click ok.

Blue dot


Simulation

GO to Momentum/Simulation/ S-parameters..

Define Simulation Frequency and sampling points

Click update

Click Simulate

Pre ADS 2011 ��


Simulate• New in ADS 2011 � use the EM button

Options:

Simulator: Momentum RF is

faster, but Momentum Microwave

is more accurate.

Something is missing!


ADS 2011 Substrate Editor

• In Substrate editor � create a new substrate

• For Example, 2 layer board

– 12mil thick FR4 substrate

• εr = 4.5, tanD = 0.025

– Top conductor

• Thickness: 1.4mil (1oz.)

• Copper (σ = 5.8e7 S/m)


Result

After Simulation is completed, S-parameters plots will be generated


ADS & Momentum:

Exporting/Importing Simulation

Data

ECE 6360: Microwave Design

Spring 2015


Simulating with Lumped Elements• Important thing to remember: Momentum is an EM simulator, and will

NOT take into account discrete (lumped) elements (ie. Resistors, caps,

inductors)

• 1.) Design & simulate your circuit in ADS schematic as you normally would

• 2.) In Layout, place ports where the terminals of the lumped elements

would be (usually at the end of the solder pads)

• 3.) Proceed to simulate layout in Momentum

Run

Momentum

simulation

For Example:

Layout creates a resistor

placeholder

Delete the place holder and

place ports on the resistor

terminals

In this circuit, I have a resistor

between two transmission

lines

Generate

Layout

Using this button:


Exporting/Importing Simulation Data

• The resulting simulation does not have the lumped element components

included, so we need to add them separately:

• 1.) Once the Momentum simulation has finished, export the S-parameter

data to an *.snp file (the “n” in the extension is the number of ports that

are in the structure. This is called a Touchstone file), by doing the

following:• Click the Data File Tool:

Select the name of the dataset

of the momentum simulation

(it is the name of the window

where you see the Momentum

simulation results)

Select this to

generate the

*.snp file


Simulating with Lumped Elements• In the ADS component library, select “Data Items”

• Data Component looks like this:

Select the “S” block

with the correct

number of ports in

your structure

For this example, I have 5

ports, so I will use this

component

Go ahead and ground

the “Ref” terminal.

Now, double click the

component and browse

and select your *.snp

file and click OK.

Place the ports and

lumped elements

accordingly. In the

layout slide, I had a

resistor between ports 4

and 5, which is what is

shown in this schematic

45

hp-ads tutorial 2015

Documents

2015ece6360 spring

microwave design1232variables

microwave applications

microwave design832linecalce

parameter palette palettes

param palette

lumped elements palette

maximum value