hfss 3d layout for 3d em simulation of planar … 3d layout for 3d em simulation of planar structure...

© 2014 ANSYS, Inc. November 12, 2015 1

HFSS 3D Layout for 3D EM simulation of planar structure (PCB, RFIC, MMIC…)

Alain Michel, ANSYS

[email protected]


Two Design Interfaces

Both Require the Accuracy of 3D and HFSS

Mechanical CAD (MCAD)

Electrical Layout (ECAD)


ANSYS HFSS Simulation workflow

• HFSS 3D MCAD interface as standard

• HFSS with 3D Layout Editor (Included)

• Automated Interface for Package, PCB, or Integrated Circuit design

• 3D Layout with Integrated HFSS solve

• DC Solver

• Passive/Causal Frequency Sweeps

• Embedded S-Parameters

• Native HFSS solves from Cadence Allegro, APD, SiP, and Virtuoso

• Full-wave SPICE circuit generation

• Planar EM (2.5D Method of Moments) (Included)

– Enabled with the HFSS solve license

• Linear circuit simulator (Included)

• RF Option Add-on (HB, Transient, Envelope…)

HFSS 2014

ECAD FEM

Interface

ECAD MoM

Interface

Full Linear

Circuit

Analysis

3D FEM

Interface

4 © 2013 ANSYS, Inc. November 12, 2015 ANSYS Confidential © 2013 ANSYS, Inc. November 12, 2015 ANSYS Confidential

Stackup Definition

• Standard HFSS design entry uses 3D Object

• HFSS in Designer combine 2D drawing with stackup definition

+ =


HFSS Meshing Techniques

• Classic • Approach: Starts with a 3D surface triangular mesh on all objects and generate a 3D volume

mesh throughout simulation domain

• Availability: HFSS (traditional 3D interface) and HFSS 3D Layout

• Pro: Works for any arbitrary 3D geometry

• Con: For complex, many layered geometries can require a long time to generate

• PhiNew

• Approach: From a layout, generate layer by layer 2D triangular mesh. Sweep mesh in stackup (+z) direction to generate tetrahedral mesh elements

• Advantage: Skips heavyweight ACIS and 3D surface mesh generation

• Availability: HFSS 3D Layout only

• Pro: Extremely fast relative to classic 3D mesh approach

• Con: Only works for stack-up or ‘swept in Z’ geometries. IC components and packages, PCBs. etc.


Enhanced Meshing = Faster Run Times

HFSS 3D CAD HFSS 3D Layout

Initial Mesher Classic Phi

Initial Mesh Size (tets) 763, 953 712, 536

Initial Mesh Time 1hr 20min 4min

Number of Adaptive Passes 6 7

Number of Tets - Final 1, 617, 954 1, 620, 969

Adaptive Passes Run Time 4hrs 1min 1hr 5min (3.7X faster)

RAM 47.6 GB 49.6 GB

Release v2014.0 November 12, 2015 L1-0: 7 © 2014 ANSYS, Inc.

Phi versus Classic: RFIC application

HFSS 3D Layout HFSS 3D Layout

Initial Mesher Classic Phi

Initial Mesh Size (tets) 274, 461 106, 167

Initial Mesh Time 1hr 06min 50sec

Number of Adaptive Passes 6 9

Number of Tets - Final 607, 630 552, 970

Adaptive Passes Run Time 1hrs 55min 50min (~2X faster)

RAM 8.85 GB 9.65 GB

P1 p2

RFIC Finger CAP courtesy of Wilocity

Capcitance value@10GHz Pass 4 8mn 0.5560pF Pass 6 19mn 0.2446pF Pass 7 27mn 0.2150pF Pass 8 38mn 0.2069pF Pass 9 53mn 0.2034pF


Test Case 1: Spiral Inductor on 1 Metal Layer

2014-02-19 Copyright © Infineon Technologies AG 2013. All rights reserved.

Original Virtuoso Cell view

ANSYS Cell view (automatic cluster of VIAs pattern)


3D View of Inductor in ANSYS HFSS 3d Layout


Test Case 1 Simulation Performance Comparison

Tool Simulation Time

(hh:mm:ss) Resources

ANSYS HFSS

(FEM)

L convergence 00:06:00 8 CPUs; 610 MBytes

L + Q

convergence 01:08:00 8 CPUs; 5.04 GBytes

ANSYS Planar EM (MoM) 00:06:00 8 CPUs; 1.15 GBytes

Tool 3 (MoM) 00:23:00 16 CPUs; 213 MBytes

Tool 4 (MoM) 00:11:00 16 CPUs; 973 MBytes



Test Case 2: Spiral Inductor on 3 Metal Layers

Original Virtuoso Cell view

ANSYS Cell view (automatic cluster of VIAs pattern)

Original Layout (directly exported from Virtuoso)

Simplified Layout (reduced layout complexity at VIA layers)

Necessary Layout Modification


The original layout directly exported from Virtuoso has a very complicated 3D structure due the Via pattern huge mesh density that leads to an inefficiency on MoM

A layout simplification was done in order to solve the inductor with MoM within a reasonable time

Port1 Port2

Port1 Port2

Port1 Port2

Port1 Port2

Test Case 2 Simulation Performance Comparison

Tool Simulation Time

(hh:mm:ss) Resources

ANSYS

HFSS

(FEM)

Original layout 00:25:00 8 CPUs ; 1.5 GBytes

Modified layout 00:24:00 8 CPUs ; 1.56 GBytes

ANSYS

Planar EM

(MoM)

Original layout N.A.

(>>1 day : aborted) > 70 GBytes

Modified layout 03:10:00 8 CPUs ; 6.3 GBytes

Tool 3 (MoM) Modified layout 07:48:00 12 CPUs ; 14 GBytes

Tool 4 (MoM) Modified layout 04:27:00 16 CPUs ; 14 GBytes



• Modify Stackup/Layers

– Select the menu item Layout > Layers

– Add, Remove signal or dielectric layers

• Parameterization – Parametric Design Environment

• Fully parameterized geometry and stackups

• New stackup dialog with laminate mode

• Visibility-by-type

• XML read/write

• Surface Roughess – Hurray or Groise Model

• Per Layer based

• Per polygon based

Layer Stackup Editor

Layers/Stackup


• Create Gap Coax Port – As simple as Draw > Port > Create or

– Select Edges Port > Create Edge Port

• Vertical or Coaxial

Inteligent Automatic Ports Creation


• Automatic Ports Setup – Right click > Select Edges > “Click on Ports Edges”

– Wave or Lumped ports depending on routing type

Wave or Lumped Ports

Gap (Lumped) Port

Wave Port

Convert

Lumped to Wave Port

video

PortDefinition/PortDefinition.mp4


Embedded Components • S-parameters or RLC components

– No requirement to mesh a boundary condition or to add ports for connecting terminals of a device

– Includes ability to represent these component models via S-parameters


HFSS Extent and Air Box setup


Post-Processing

• Rectangular, smith chart … plots

• Current, far and near field display

• Meshing

2.00 4.50 7.00 9.50 12.00 14.50 17.00 19.50F [GHz]

-37.50

-25.00

-12.50

0.00

Y1

Ansoft LLC spir2_20S11_12_dB ANSOFT

Curve Info

S12_3D_HFSSSetup HFSS_gap : Sw eep 1

S11_3D_HFSSSetup HFSS_gap : Sw eep 1

5.002.001.000.500.200.00

5.00

-5.00

2.00

-2.00

1.00

-1.00

0.50

-0.50

0.20

-0.20

0.000

10

20

30

40

50

6070

8090100110

120

130

140

150

160

170

180

-170

-160

-150

-140

-130

-120-110

-100 -90 -80-70

-60

-50

-40

-30

-20

-10

spir2_20Smith Chart 1 ANSOFTCurve Info

S(Port1,Port1)Setup HFSS_gap : Sw eep 1


Integration in existing flow


Integration in Existing Flow

• GDS Import Layout geometry is imported into HFSS 3D Layout with layer stackup defined.

All information for material properties, layer type, elevation and thickness are

automatically set with regards to .xml file information.

• Cadence Virtuoso Integration Set-up and solve HFSS simulations without leaving the Cadence environment

• Microwave Office Link For HFSS 3-D layered geometries, the exporting of the stack-up, material properties,

boundary conditions and port settings are all included when you click “export to

HFSS” from within the MWO software.


Thank you

hfss 3d layout for 3d em simulation of planar … 3d layout for 3d em simulation of planar structure...

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