Download - HFSS 12.0 Tips and Techniques for HFSS Project Setup and Solve

© 2009 ANSYS, Inc. All rights reserved. 1 ANSYS, Inc. Proprietary© 2009 ANSYS, Inc. All rights reserved. 1 ANSYS, Inc. Proprietary

HFSS 12.0Tips and Techniques

for HFSS project setup and solve

HFSS 12.0Tips and Techniques

for HFSS project setup and solve

© 2009 ANSYS, Inc. All rights reserved. 2 ANSYS, Inc. Proprietary

Agenda

Ansoft HFSS v12

– Enhancements: GUI, Mesh, & Solver

– New Features: GUI, Mesh, & Solver

– Platform Support


Ansoft HFSSCore Technologies

GUIGUI

MeshMesh SolverSolver

HFSS v12 released on September 10th, 2009


Enhancements Summary

Mesh

64-bit Volumetric MeshCurvilinear elementsInitial Mesh Settings

Increased Speed

Mesh


Increased Speed

Solver

Mixed Element OrderDomain Decomposition Method

Dependent SolvePort Solver with DC Extrapolation

Solver



Graphical User Interface

Near and Far Field OverlayAdjoint Derivatives

Imprint and Select by AreaClip Plane and Polyline cross section





Enhancements








Overlay Near and Far Field Plots on Geometry

• Visualize far-field and near-field radiation patterns on model geometry• Control transparency and/or size of pattern overlay


Edit Sources with Port Post-Processing

• Option for port post-processing to affect sources for field plots


Edit Sources with Port Post-Processing

• Fields correspond with deembedding

Original geometry for ring hybrid model

Modified geometry with new port location disrupts

field behavior Operation restored by de-embedding


Streamline Plot

• New plot type for field quantities– Pick source face, choose Poynting Vector and Streamline option


Post-Processing Variables

• Can be modified without re-simulating the model

• Can optimize complex weights of antenna elements in phased array

Optimization of Phased Array Excitations

Synthesized Far-field Pattern Specify Desired Scan Angle and Maximum Sidelobe Level


Adjoint Derivatives

• Derivatives of S-Parameters with respect to Design Variables– Identify which parameters influence output most– Plot both S-parameters and its derivatives– Focus on sensitive design parameters– Enhanced optimization


Plotting with Derivative Offsets

Dipole ModelLengthRadius

“Tune” the delta for a given variable…

• Tune reports and explore effects of small design changes– Real-time tuning shows impact on performance

– Tune offsets for variables included in derivative setup


Expression Cache

• Evaluate and save any expression versus adaptive pass– Includes scalar and radiated field data– Enables multiple convergence criteria– Use Quick Report to generate Convergence Plot

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00Pass

1.00

10.00

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Y1

Ansoft LLC HFSSModel1Expression ConvergeCurve Info

ExprPctDelta(L1)Setup1 : AdaptivePassFreq='12GHz'

ExprPctDelta(Q1)Setup1 : AdaptivePassFreq='12GHz'

ExprPctGoal(L1)Setup1 : AdaptivePassFreq='12GHz'

ExprPctGoal(Q1)Setup1 : AdaptivePassFreq='12GHz'


Imprint

• Imprint– Imprint the geometry of one object upon another

Face created from imprint


Imprint Projection

• Imprint Projection– Patch Antenna Array Imprinted on a Nosecone

• Results in Faces of original object imprinted• Make sure that the distance selected is greater than the

distance between the antenna and nosecone


Enhanced Usability

• Select 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

• Select By Variable– Helps find objects tied to variables

• Select By Area– By default, only items with external surfaces are

selected

• Material filters– Enable the Include and Exclude radio buttons

• Object name filters– Enable the Exclude and Include check boxes

• Object type filters – Enable the check boxes for including Solids,

Sheets, and/or Lines

• Hide unfiltered objects – Makes unfiltered objects transparent after selection


Enhanced Usability

• Multiple lumped port assignments– Multi port selection– Assign ports and reference

• Useful for SI problems with multiple lumped ports


Enhanced Usability

• Clip plane– Interactively slice through arbitrary plane– Can view model geometry, mesh plots, field plots, etc.


Definable Polyline Cross Section

• Create 2D or 3D objects from polylines– Choose Cross Section Type and Size– Section is automatically swept along the polyline

• Very useful for creating parameterized geometry– Ports, traces, bends,…


2D Chamfers and Fillets

• Create Chamfers and Fillets on 2D Objects– Select a vertex graphically and choose the menu item:

• Fillet or Chamfer

Chamfer - 45 degree cut

Fillet- Rounded edge


Additional GUI Enhancements

• Duplicate Mesh Operations with objects• Wrap Sheet command• Draw Region command• Create parametric setup from file• Enable/Disable History editing information

– Recreates the history for polylines, circles, or ellipses • Save Sweep settings as defaults• Model Validation settings

– Strict, Warning, Basic• Warning message about object intersect

– RMC on message takes you to region of intersect


New Plot Types

• Rectangular Stacked Plot– Plot all variations in stacked format

1.00 1.50 2.00 2.50 3.00 3.50Freq [GHz]

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Curve Info

dB(St(coax_pin_T1,coax_pin_T1))Setup1 : Sweep1feed_xpos='-0.5cm' feed_ypos='-0.5cm'

dB(St(coax_pin_T1,coax_pin_T1))Setup1 : Sweep1feed_xpos='0cm' feed_ypos='-0.5cm'

dB(St(coax_pin_T1,coax_pin_T1))Setup1 : Sweep1feed_xpos='0.5cm' feed_ypos='-0.5cm'

dB(St(coax_pin_T1,coax_pin_T1))Setup1 : Sweep1feed_xpos='-0.5cm' feed_ypos='0cm'

dB(St(coax_pin_T1,coax_pin_T1))Setup1 : Sweep1feed_xpos='0cm' feed_ypos='0cm'

dB(St(coax_pin_T1,coax_pin_T1))Setup1 : Sweep1feed_xpos='0.5cm' feed_ypos='0cm'

Ansoft LLC HFSSDesign1XY Stacked Plot 1


User Defined Shortcuts

• User Definable Keyboard Shortcuts– Define, load or save shortcut keys to common commands


Enhancements

Mesh

64bit Volumetric MesherCurvilinear elementsInitial Mesh Settings

Increased Speed

Mesh

64bit Volumetric MesherCurvilinear elementsInitial Mesh Settings

Increased Speed


Mesh Generation

– Updated Geometry Kernel (ACIS R19 SP2)

– New Meshing Technology:• Curvilinear elements

– True surface representation• New Ansoft TAU Mesher introduced

– Strict and Tolerant mode depending on model geometry

– Adaptive meshing improvements:• Higher Quality Mesh

– Faster and more efficient simulations• Reduced CPU time - Faster


Curvilinear Elements

• Right-click on Mesh Operations -> Initial Mesh Settings– Curvilinear Elements Off by Default

• Apply curvilinear elements

Curvilinear mesh element

HFSS 12 can use either mesh element

Coarse mesh Fine mesh


Initial Mesh Settings

• Right-click on Mesh Operations– Auto is the default setting– Ansoft TAU Mesh

• Strict and Tolerant– Ansoft Classic Mesh


New default mesh generator

HFSS 11

HFSS 12 meshes it cleanly.


Enhancements

Solver



Remote Solve Manager

Solver



Remote Solve Manager


Solver Technology Overview

• Solution Options– Direct

• Default technique• Solves matrix equation Ax=b

– Multi-frontal Sparse Matrix Solver to find the inverse of A– Solves for all excitations(b) simultaneously

– Iterative• Added in V11• Solves matrix equation MAx=Mb

– M is a preconditioner– Major computation is the matrix-vector multiplication: (MA)x– Iterates for each excitation – Simultaneously solve using SMP (MP/HPC License)

• Iterative Solver is more sensitive to mesh quality– Benefits from TAU Meshing


Solver Technology Overview

• Order of Basis Functions– Hierarchical basis functions

• Introduced in V11• Zero or First or Second order basis functions• Higher-order elements have increased accuracy• One order per mesh allowed

– Mixed Order New

• hp-FEM Method– Refines element order(p) and element size(h)

• Automatically distributes element order based on element size

• Generates optimum combination of hierarchical basis functions (Zero and First and Second)– Efficient use of computing resources


Mixed Element Order Example #1

• Two waveguide horn antennas• Compared element order of

basis functions– Iterative matrix solver– Mixed order reduces solver time by

100% and RAM usage by 40%

Element Order

Iterative Solver Real Time

(Adaptive Pass)

RAM Usage

Mesh Elements

First 7 min 4.5 GB 336k

Mixed 3 min 2.8 GB 58k

Probe-fed Pyramidal Horns


Mixed Element Order Example #2

Element Order

Direct Solver Real Time

(Adaptive Pass) RAM Usage

First 1hr 20min 13.8 GB

Second 4hr 45min 16.6 GB

Mixed 56 min 13.7 GB

• Finite array of helix elements• Direct matrix solver

– Mixed order reduces solver time by 30%

Finite Phased Array


Ports Precision

• HFSS v12 Port Solver• 50 ohm coax adapter with Teflon

support slug• In v11 solve down to 50 kHz

– Fails if frequency is lower• How much lower and more

accurate can v12 solve


Ports Precision Results


Port Precision Results, cont.

• Reliable results in v11 to 630 kHz• In v12 ~ 2.5 kHz (4e-3 lower)• Lower “noise floor”.

– V11 = -110 dB– V12 = -120 dB

• Can expect a 2-3 order in magnitude lower “solvable” frequency– Improves DC Extrapolation

• Important for SI designs.


Domain Decomposition for HFSS

• New feature in HFSS v12• Distributes mesh sub-

domains to network of processors

• Distributed memory parallel technique

• Significantly increases simulation capacity– 64-bit meshing

• Highly scalable to large numbers of processors

• Multi-processor nodes can be utilized

HPC distributes mesh subdomainsto networked processors and memory


Review DDM Technique

• DDM subdivides a mesh into smaller mesh “sub-domains” that are solved in parallel.– A “master” node iteratively solves for total solution– Subdivision into domains is automated

• Easy to use!!!• The user defines a set of N available compute nodes to

be used for a DDM solution– n=1 is the “master” node, single core– n=2 to N are the sub-domain nodes solved with direct

solver


DDM Setup Interface

• Tools -> Options -> General Options -> Analysis Option• Tools -> Options -> HFSS Option -> Solver• HFSS -> Analysis Setup -> Add Solution -> Setup Options

Master node

Domain nodes


Observing a DDM solution

1. Six sub-domains solvinga. 7th master node

or core at top2. Four sub-domains

finished, two running

3. Sub-domains finished; Master core iteratively reconstructing solution

4. Post-processing data

5. Transferring files


Hardware Suggestions

• Suggested: 4GB minimum per core• Master node:

– Should have a “decent” amount of shared memory.– 4-16 for large problems – >16 for the largest (100+ cores)

– For very large simulations with many domain nodes the iterative process on the master node will be the most computationally expensive

• It is more important to use memory efficiently than to use all the processors.


Example #1: F-35 - JSF

•F-35 Joint Strike Fighter: UHF blade antenna @ 350 MHz•Problem size = 1400λ3


• Consistent results between domain decomposition and direct solver

Results and Accuracy


Faster Solutions

• Solution timeNumber of Domains Time (secs)

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 17.71

Iterative 1 4815 4.83

Time (secs)

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Time (secs)

Speed-up

123456789

101112131415161718

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Speed-up


Memory Savings

Number of Domains

total memory

average memory

1 33.30 33.30

2 28.43 14.22

3 27.46 9.15

4 24.89 6.22

5 24.88 4.98

6 23.94 3.99

7 23.53 3.36

8 23.25 2.91

9 22.15 2.46

10 21.06 2.11

11 21.97 2.00

12 20.64 1.72

13 20.96 1.61

14 20.49 1.46

15 20.18 1.35

total memory

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total memory


Example #2: Asymmetric Dish Antenna

Total cores Elapsed Time (S) Memory (GB) Speed-up Linear8 22049 153.7 1.00 1.0012 12948 133.5 1.70 1.5016 9540 123.6 2.31 2.0020 7345 114.6 3.00 2.5024 5649 110 3.90 3.0028 4829 107.7 4.57 3.5032 4560 103.7 4.84 4.0036 4102 101.2 5.38 4.5040 3912 96.4 5.64 5.00

~17,500 λ3

9-16 saves 12509 s =(22049-9540)17-24 saves 3891 s Diminishing absolute returns

Not an image of actually model simulated


• Exhibits better than linear speed-up wrt number of cores– 8 to 32 = 4.8X speed-up.

• 67% memory savings from 8 to 40 cores• How does it compare to a single processor

direct solve?– Answer: Could not be accomplished on a single

machine. “Solving the previously unsolvable.”

Example #2: Summary


Remote Simulation Manager

• New for Distributed Analysis and Remote Simulations– Easy to setup and use

• Enables DDM, DSO and remote solve capabilities– Supports mixed operating system environments– Supports LSF and Windows HPC


Platform Support

• Windows (32/64)– XP Professional– Vista– HPC Server 2008– Server 2003

• Linux– Red Hat Enterprise 4/5– Suse v10 and v11


Summary

Mesh


Increased Speed

Mesh


Increased Speed

Solver



Remote Solver Manager

Solver



Remote Solver Manager





