HFSS - FEA, CFD and Explicit Dynamics



ANSYS HFSS software is the industry-standard simulation tool for 3-D full-wave electromagnetic field simulation and is essential for the design of high-frequency and high-speed component design. HFSS offers multiple state-of the-art solver technologies based on either the proven finite element method or the well established integral equation method. You can select the appropriate solver for the type of simulation you are performing.

Engineers rely on the accuracy, capacity, and performance of HFSS to design high-speed components including on-chip embedded passives, IC packages, PCB interconnects and high-frequency components such as antennas, RF/microwave components and biomedical devices. With HFSS, engineers can extract scattering matrix parameters (S,Y, Z parameters), visualise 3-D electromagnetic fields (near- and far-field) and generate ANSYS Full-Wave SPICE models that link to circuit simulations. Signal integrity engineers use HFSS within established EDA design flows to evaluate signal quality, including transmission path losses, reflection loss due to impedance mismatches, parasitic coupling and radiation.

Each HFSS solver is based on a powerful, automated solution process where you are only required to specify geometry, material properties and the desired output. From there HFSS will automatically generate an appropriate, efficient and accurate mesh for solving the problem using the selected solution technology. With HFSS the physics defines the mesh; the mesh does not define the physics.

ANSYS HFSS software contains the technology, solvers and capabilities needed to model RF and microwave as well as signal- and power-integrity issues.

Product Features Include:
Automatic Adaptive Meshing

A key benefit of HFSS is its automatic adaptive meshing techniques where you are only required to specify geometry, material properties and the desired output. The meshing process uses a highly robust volumetric meshing (TAU) technique and includes multi-threading capability that reduces the amount of memory used and speeds the simulation time. This proven technology eliminates the complexity of building and refining a finite element mesh and makes advanced numerical analysis practical for all levels of your organisation.

ANSYS HFSS Antenna Automated Adaptive Meshing
ANSYS HFSS Antenna Automated Adaptive Meshing


Solver Technologies

HFSS offers multiple state-of the-art solver technologies each based on the proven finite element method. Users select the appropriate solver for the type of simulation they are performing.

  • Frequency Domain Solver
  • HFSS Transient Solver
  • HFSS Integral Equation (IE) Solver
  • Hybrid Finite Element – Integral Equation Method (FE-BI) Solver
  • Physical Optics Solver
Advanced Finite Array Simulation Technology

ANSYS HFSS allows for the calculation of finite arrays that include all electromagnetic effects including element-to-element coupling, and the critical edge effects.

ANSYS HFSS Antenna Finite Array
Far field antenna patterns of finite array calculated with HFSS. Graph on right shows effect of finite array (solid lines) size on sidelobes when compared to infinite array (dashed lines)

This new technology leverages the repeating nature of array geometries and can be used with our HPC capability to obtain a very fast solution time for large finite arrays.

Mesh Element Technologies

ANSYS HFSS software utilises tetrahedral mesh elements to determine a solution to a given electromagnetic problem. These mesh elements in combination with the adaptive mesh procedure create a geometrically conformal, and electromagnetically appropriate, mesh for any arbitrary HFSS simulation. This ensures that HFSS will provide the highest fidelity result for any given simulation. In addition to the standard first-order tetrahedral mesh HFSS can also employ zero-order, and second-order elements as well as a mixture of elements of different order. Using mixed-order elements enables HFSS to assign an element order based on the element size which creates an exceptionally efficient mesh and overall solution process.

In addition to the mixed order elements HFSS also allows the use of curvilinear elements. These elements are perfectly conformal to any associated curved surface. This then will provide the highest degree of accuracy possible as absolutely no assumptions or tessellation is performed.

HFSS Mesh Elements
Conformal curvilinear adapted mesh


Leading Solution Technologies

HFSS contains a number of technologies specifically designed to increase the accuracy of simulations and/or reduce the overall simulation time. These technologies are:

  • Direct and iterative matrix solvers (32- and 64-bit)
  • Accurate broadband frequency sweeps with rigorous treatment of dispersive ports, materials and skin effect
  • Advanced frequency-dependent materials and Huray surface roughness models
  • Floquet ports for antenna arrays, frequency-selective surfaces (FSS) and other periodic structures
  • Eigenmode matrix solver (32- and 64-bit) including periodic boundary conditions for traveling-wave and electromagnetic band-gap structures
  • Strong CAD integration capabilities including model healing and automatic feature recognition with mesh resolution control
Advanced Broadband SPICE Model Generation

ANSYS Full-Wave SPICE enables frequency-dependent SPICE models for accurate time domain simulation in third party time domain analysis tools. It provides high-bandwidth SPICE models at the touch of a button. Full-Wave SPICE models can be created for use with Nexxim®, HSPICE®, Spectre® RF and MATLAB®. Full-Wave SPICE is the only tool on the market that that produces highly accurate, high-bandwidth SPICE models at the touch of a button. This capability enables engineers to design electronic and communication components while taking Gigahertz-frequency effects into account.

Optimisation and Statistical Analysis

ANSYS Optimetrics is a versatile, optional software program that adds parametric, optimisation, sensitivity and statistical analysis capabilities to HFSS. Optimetrics automates the design-optimisation process for high-performance electronic devices by quickly identifying optimal values for design parameters that satisfy user-specified constraints.

Coupled to ANSYS electromagnetic-field simulation software, Optimetrics delivers optimised designs that favorably impact the bottom line.



  • Parametric analysis
    • User-specified range and number of steps for parameters
    • Automatic analysis of parameter permutations
    • Distributed Solve (cost option)
      • Automated parser management across multiple hardware platforms and reassembly of data for parametric tables and studies


  • Optimisation
    • User-selectable cost functions and goal objective
      • Quasi-Newton method
      • Sequential Nonlinear Programming (SNLP)
      • Integer-only Sequential Nonlinear Programming
    • Automatic analysis of parameter variants until optimum goal obtained


  • Sensitivity analysis
    • Design variations to determine sensitivities:
      • Manufacturing tolerances
      • Material properties


  • Tuning
    • User-controllable slide-bar for real time tuning display and results


  • Statistical analysis
    • Design performance distribution versus parameter values


EDA Design Flow Integration

Signal integrity engineers use HFSS within established EDA design flows to evaluate signal quality, including transmission path losses, reflection loss due to impedance mismatches, parasitic coupling and radiation.

High-Performance Computing (HPC)

ANSYS HFSS offers a number of high-performance computing (HPC) options to enable engineers to fully utilise existing clusters to achieve the fastest simulation solution time possible.


The multiprocessing option is used for solving models on a single machine with multiple processors or multiple cores which share RAM (when the models fit into this amount of RAM). Multiprocessing is enabled via the new HFSS HPC option.

Domain Decomposition Method (DDM)

DDM automatically splits the finite element mesh of your geometry into a number of smaller meshes, called domains, of approximately equal sizes. HFSS determines the optimum number of domains, depending on the mesh size and the number of computers and processors available. The domains are analysed separately on the network, after which an iterative procedure on the domain interfaces reconstructs the full solution as if the entire model had been simulated on one computer. This allows the simulation of very large models when one machine might not have enough memory. DDM reduces simulation time, offering a near-linear speedup with each additional processor. DDM is enabled via the HFSS HPC option.

Diagram showing how DDM can be used to solve a very large HFSS model


Distributed Solve

Distributed solve allows a single user to distribute parametric studies or frequency points across a number of machines to expedite total simulation time. This time-saving capability splits multiple pre-defined parametric design variations and/or frequency points, solves each simulation instance on a separate machine and then reassembles the data. This dramatically accelerates parametric studies and design optimisation.

Powerful Post-Processing Capabilities

HFSS provides powerful post-processing features to visualise, animate and report the results of your simulation.

  • S-parameters (single-ended, differential, de-embedded, renormalised)
  • Y and Z matrices
  • Port mode and impedance calculation by 2-D eigenmode solver fields


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