introducing hfss version 12

© 2008 ANSYS, Inc. All rights reserved. 1 ANSYS, Inc. Proprietary

Introducing HFSS Version 12

Matthew H. Commens, Ph.D.Product ManagerAnsoft HFSS


…achieve a dramatic reduction in development time and costs while at the same time realizing increased reliability and…

…high-performance computing enhancement, domain decomposition…simulate and design at a scale and speed never before possible.

…ANSYS follows through on its commitment to deliver technology with unequalled depth and unparalleled breadth…

“HFSS 12.0 is a breakthrough in high-frequency electromagnetic field simulation,” said Zol Cendes, chief technology officer at Ansoft. “For the first time, engineers are able to solve vast electromagnetic field problems with speed, efficiency and accuracy. “

HFSS 12.0


HFSS 12: New Features

New Solver Technology

New Meshing Technology

New Element Technologies

Adjoint Method Based Derivatives

Integration with ANSYS DesignXplorer

Improved GUI and Modeler


New Solver TechnologyDomain Decomposition


Simulating Large

•F-35 Joint Strike Fighter: UHF blade antenna @ 350 MHz•L = 18.6λ, V = 806λ3


“Divide and Conquer”


Domain Decomposition

• Distributed memory parallel solver technique

• Distributes mesh sub-domains to network of processors

• Significantly increases simulation capacity

• Highly scalable to large numbers of processors

• Automatic generation of domains by mesh partitioning

– User friendly– Load balance

• Hybrid iterative & direct solver– Multi-frontal direct solver for

each sub-domain– Sub-domains exchange

information iteratively via Robin’s transmission conditions (RTC)

Distributes mesh sub-domainsto networked processors and memory


18X Speed-up with 15 Domains

Number of domains Time (sec) Speed-up

1 23252 1.00

2 8928 2.60

3 6056 3.84

4 4479 5.19

5 3476 6.69

6 2784 8.35

7 2649 8.78

8 2180 10.67

9 2032 11.44

10 1760 13.21

11 1859 12.51

12 1804 12.89

13 1527 15.23

14 1649 14.10

15 1313 17.710

5000

10000

15000

20000

25000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Time (secs)

Time (secs)

123456789

101112131415161718

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Speed-up

Speed-up

Superlinear performance!


• Consistent results between domain decomposition and direct solver

Results and Accuracy


Humvee with Patch Antennas

• Two L-band patch antennas located on roof of Humvee– Fed using TM20 mode to excite

monopole far-field pattern• Bounding airbox is 12.5λ x 22λ x

8λ or 2200λ3

6 domains Domain Solver

Total Memory 4.5 GB

Average Memory 0.75 GB

Solution Time 25 min

1st order basis functions. Performed 8 passes to reach ΔS = 0.02


WLAN Access Point and Printer

• Wireless printer and router in typical office environment – 2.44 GHz solution frequency

• Room size is 25λ x 25λ x 22λ or 13750λ3

• Solved on 16 core AMD Opteron workstation

• Printer-to-router coupling: -57 dB

15 domains Domain Solver

Tetrahedra 846k

Total Memory 32 GB

Average Memory 2.0 GB

Solution Time 5 hr 20 min


Metallic Sphere

• Mie scattering from a PEC Sphere– 100λ in diameter

– Distributed to 30 cores across four networked computers

• Re-calibrate your Expectation!

9M tetrahedra, 64-bit meshing

51M unknowns (matrix size)


Domain Decomposition ExampleAntenna Integration on Spacecraft


Antenna Element Design

• Operating criteria– 3-4 GHz frequency band– 50 Ω input impedance

• Axial mode helix selected as antenna– Endfire radiation with moderate gain– Right-hand circular polarization– Wide bandwidth– Simple feed– High radiation efficiency

• Orthogonal support dielectric along helix• Coax probe feed extends above antenna

ground plane• Simulation with direct solver

– 200k unknowns in 1.2 GB


Finite Array Model

• 7-element array model with finite ground plane– Includes edge effects– Includes mutual coupling

between elements

Fields with All Element Excited

Far-field Pattern for Broadside Beam

Far-field Pattern for Broadside Beam


Installed Array on Spacecraft

• Good correlation with isolated array patterns

• L = 78 λ, V = 31,000 λ3

– 25M unknowns– 12 hr runtime, 35 cores

• Recalibrate your expectations!



model

Geometric healing or repair(For model defects)

Surface mesh generation

Volume mesh generation

HFSS 11(bottom up algorithm)

Surface Mesh

Volume Mesh

model

Volume mesh generation

Adapt mesh to conform to geometry

Conformal surface mesh generation

HFSS 12(top down algorithm)

Surface Mesh

Volume Mesh


TAU Mesher

• Mesh a higher percentage • Effective on imported geometries• Higher mesh quality• fewer total elements• smoother element transition• Automatically healing and repair.

v11

v12


Molex Backplane Connector

•11.0 Initial Mesh: 631862•12.0 initial Mesh: 227517, ~63% reduction in initial mesh size•Mesh reduction directly translates to reduction in memory and solution time

Fewer, higher quality mesh elements


New Element TechnologyCurvilinear Elements


Curvilinear Elements

• Most accurate solution to fields on curved structures

• Mesh adapted about curved or true surfaces

• Element matrices computed using the curved boundaries

• Reduces solution time and RAM usage– A smaller, coarser mesh

achieves equivalent accuracy

Rectilinear mesh element Curvilinear mesh element

Red – HFSS

Blue – Analytic Curve10 cm radius PEC sphere solved from 0.040 - 2 GHz


SLAC Beam Former

11426.0 11426.5 11427.0 11427.5 11428.0 11428.5 11429.0 11429.5 11430.0Freq [MH z ]

-40

-35

-30

-25

-20

-15

-10

-5

0

Ret

urn

Loss

TM

01 m

ode

(dB

)

Ansoft LLC truesurfaces_longerXY P lo t 4Curve Info

dB(S(WavePort1:3,WavePort1:3))Setup1 : Sw eep1SA ='22.5deg'

Measurements 11,428.4 +- 0.5 MHz

E-field along Z


Resonator with Concentric Spherical Dielectrics

I Wolff, “A generalized description of the spherical three-layer resonator with an anisotropic dielectric material,” IEEE AP Symp, June 1987, pp. 307-310

Faceting f (GHz)45˚ 8.7530˚ 8.5415˚ 8.5310˚ 8.407.5˚ 8.405˚ 8.39

22.5˚ 8.38

ΔF=0.1% Mesh Time

10˚ rect. 53k 16:40

22.5°curv. 6k 00:55

• Fewer curvilinear elements yield same accuracy as rectilinear

– 88% fewer tetrahedra– Runs 16X faster


New Element TechnologyMixed Element Orders


Mixed Element Orders

• Automatic localization of basis functions

• Refinement via element size and order

• Locally efficient use of computing resources

First-Order, 16:23, 1.40GB

Mixed-Order, 7:55, 0.985GB


Log Periodic over EBG Groundplane

• High geometric detail with large homogeneous radiation volume

• Compare mixed order vs. 1st

order– 28% reduction in solution time

– 29% reduction in memory

• Mixed order converges faster– 12 passes vs. 14 passes– Average order = 0.96

• S11 @ 12 GHz– 1st S11 = 0.86584– Mixed S11 = 0.86511


Introducing Adjoint Method Based Deriviatives


Adjoint Derivatives

• New Capability for sensitivity, tuning, and optimization• Compute the derivatives of SYZ parameters with respect to project and

design variables• Eliminates need to solve multiple variations with small differences and

numerical noise– More efficient and more accurate

• Provides real-time tuning of reports to explore effects of small design changes• Improves derivative-based optimization methods

2008 IEEE MTT-S Digest, pp. 527-530


Sensitivity of |S11|, Combline Filter

-15000

-10000

-5000

0

5000

10000

99.15 9.39.45 9.69.75 9.9

10.0510.2

10.3510.5

10.6510.8

10.95

freq [GHz]

dS11

dp [

1/m

]

-60

-50

-40

-30

-20

-10

0

|S11

| [d

B]

d|S11|_dRid|S11|_dG1d|S11|_dG2|S11|

This filter design is:- Most sensitive to change in gap G2- Least sensitive to change in coax radius Ri

G2 G1G2

Ri

Ri

G1 – gap between centertuner and resonator

G2 – gap between off-centertuners and resonators

Ri – inner radius of coax feed

Note: for sensitivity with respect to Ri, ports are involved


Local Derivatives Speed-up Optimization

• Goal: Minimize reflection in waveguide quarter wave transformer

• SNLP optimizer uses derivative information to speed-up calculation of response surface

Example Optimization without Derivatives

Example Optimization with Derivatives


SMA launch

• SMA launch is typical multi-variable design problem• Design variables:

– length, radius of via stub, radius of antipads, radius of signal pads, radius & antipad of ground via

• Solve for the derivatives of many variables at onceNominal Values for Design Variables

Specify Desired Derivatives in Solution Setup


Real-Time Tuning with Analytical Derivatives

• Real-time tuning shows effects of small changes on S-parameters

S-parameters of Nominal Design

S21

S11

Quickly Explore Effects of Small Changes on S-parameters

New Derivative Context in

Report Editor


Improved GUI and Modeler


Post-Processing Variables

• New type of variable whose value can be modified without re-simulating model

• Optimize complex weights of antenna elements in phased array– Optimize for side-lobe location

and main beam peakOptimization of Phased Array Excitations

Synthesized Far-field Pattern


Convergence Based on Multiple Output Variables

• Evaluate and save multiple expressions vs. adaptive pass– Includes SYZ parameters,

local, near and far field– Fully integrated with reporter

and Optimetrics


Clip Plane Viewing

• Project preview– Image and notes

available in File Open– Image available in

Windows Explorer

• Clip plane– Interactively slice

through arbitrary plane– Can view model

geometry, mesh plots, field plots, etc.


Select by Area Mode

• Enable material override– Conductors override

dielectrics– Smaller objects override

larger objects with same material

– Avoids need for explicit subtractions

• Select objects by area– Click and drag to rubber-band

select– Right-to-left selects all objects

passing through window– Left-to-right selects all objects

inside window


Overlay Far Field Plots on Model

• Visualize radiation patterns on model geometry– Control transparency and/or size of pattern overlay


Array Variables

Supported at design level only

Assign array variable to

Material property


New Modeling Commmands

• Fillets and Chamfers on 2D objects

• Sheet wrapping• Sheet and body

imprinting with projection

“Modeler/Chamfer (Fillet)”


Streamline plot of Poynting vector on this face. Streamlines originate at

discrete points on the face

Streamline plots


Integration with ANSYS DesignXplorer


ANSYS DesignXplorer in R12.1 and HFSS 12.0

WR137

WR90 Transition

length

heig

ht

width


DX – Response Surface


DX – Robust Design (DOE)


Six Sigma


Port post-processing on fields

Matched terminal s-parameters

Modeler selection by area filter

Fixed distance padding for region

User Defined Keyboard shortcuts

Expression cache

Multiple output variable convergence

Overlap/intersecting object selection from message window

ACIS R19 SP2 upgrade

Extended healing capability

Improved setup for analytic ports

Project specific script recording

Define parametric sweep from file

Improved far field data link. More efficient

Project Preview – Both file open and in Windows Explorer

Flexible history editing

Polyline cross-section

Mode filtering for report setup

HFSS 12.0: Available Now!

introducing hfss version 12

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