ANSYS HFSS has been the mainstay, gold-standard electromagnetic simulation technology for many years. There are many key pieces to its reliable technology — such as hierarchical vector basis functions for robust solutions to Maxwell’s equations, two-dimensional port solving technology, the trans-finite element method for fast extraction of s-parameter models, state-of-the-art fast and scalable matrix solving technology, and its flexible and easy-to-use parametric interfaces. Read More:

1. HFSS 3D Layout and the Phi Mesher

2. 2 © 2014 ANSYS, Inc. March 28, 2014 ANSYS Confidential
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.

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Why Phi?
Phi vs Classic
• Always wins initial mesh generation
– Including Lambda + Port Adapt
– Initial mesh size is comparable
• Can mesh bigger designs
– When combined with distributed memory solver and hardware can solve very large
and complex designs
Initial Mesh is orders of magnitudes faster!
HFSS 15: 5hrs - Initial Mesh
HFSS 2014: 11min - Initial Mesh

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• Accurate Solution
– Industry leading meshing capacity
– Causal/Passive s-parameters
– True DC solution
– Embedded RLC or s-parameter components
• Fast Simulations
– Reduces multi-day long simulations to a few
hours or less
• Ease of use – 3D Layout
– Easy translation, import and setup
– Maintains trace characteristics and nets from
layout
– Hierarchical design – Chip/Package/Board
– Embedded dielectric layers
– Parameterized model for Design Optimization
• Trace width, layer thickness, via dimensions etc.
• Manufacturing tolerances (etching factor)
• Materials
Benefits of HFSS for 3D Layout

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HFSS 3D Classic – 5hrs 15min
HFSS 3D Layout w Classic v15 – 3hrs 41 min
•HFSS 3D Layout meshing advantages
– Mesh and solve non-manifold geometry
– Mesh geometries with large aspect ratios
– Layer-based geometry is easier to edit,
modify, clean up etc.
Enhanced Meshing in HFSS 3D Layout
¼ of multilayer flip-chip package
20 nets (40 ports)
HFSS 3D Layout w Phi – 11 min

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Is there a difference between
HFSS 3D and HFSS 3D Layout ?
Solve a model in both HFSS 3D and HFSS 3D
Layout and compare
Note easy export from HFSS 3D layout to
HFSS 3D

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Multilayer complex package layout
• HFSS 3D compared to HFSS 3D Layout
HFSS 3D CAD
HFSS 3D Layout

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Initial Meshing Comparison
• Extremely fast initial Phi meshing. Phi is 20X faster!
• 4min vs. 1hr 20min
HFSS 3D CAD - Classic
HFSS 3D Layout - PHI

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HFSS 3D – Run Time
• Total: 6hrs 33min
• Adaptive Part: 4hr 1min
• Interpolating Sweep: 2hrs 32 min

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HFSS 3D Layout – Run Time
• Total: 3hrs 3min
• Adaptive Part: 1hr 05min
• Interpolating Sweep: 1hr 58 min

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HFSS CAD vs. HFSS 3D Layout
Solid HFSS 3D CAD
Dashed - - - - - - - HFSS 3D Layout
Virtually identical
results from
adaptive meshing

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Summary
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

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Is there a difference between
HFSS 3D and HFSS 3D Layout ?
Example #2: Multi-layer PCB with end to end
SMA connectors
3D components drawn as stacked up
geometry can be modeled in HFSS 3D
Layout

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HFSS 3D Geometry
• Include SMA connector body with stands (serve as ground pins)
• Account for true 3D SMA transition to PCB
HFSS 3D Solid Model Design Creation
Lumped Port dimensions
equal to connector pin dimensions

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Added SMA body geometry to a layout stackup
Port properties created automatically
HFSS 3D Layout Design Creation
Layout View
EM Design 3D View
Stackup Editor
Port/pin settings

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Results Comparison
• HFSS 3D compared to HFSS 3D Layout
Solid HFSS 3D CAD
Dashed - - - - - - - HFSS 3D Layout

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Results Comparison – Return Loss
• HFSS 3D compared to HFSS 3D Layout
Solid HFSS 3D CAD
Dashed - - - - - - - - HFSS 3D Layout

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Results Comparison – Insertion Loss
Solid HFSS 3D CAD
Dashed - - - - - - - - HFSS 3D Layout
• HFSS 3D compared to HFSS 3D Layout

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Phi meshing is a breakthrough technology for finite element mesh
generation
Provides designers of IC components, IC packages and printed circuit
boards a faster initial mesh and faster simulation
Enables even larger and more complex layered geometries to be solved
When combined with ANSYS HPC can leverage scalable and fast HPC
technologies
Distributed direct matrix solver to solve the largest design on
distributed memory
Spectral decomposition method (SDM) to solve frequency points in
parallel for faster simulations
Conclusions