How do HFSS, CST and Feko differ?
The three most widely used commercial antenna solvers are Ansys HFSS, built around an adaptive finite element method; CST Studio Suite from Dassault Systèmes, known for its time-domain finite integration technique plus frequency-domain and integral solvers; and Altair Feko, centered on the method of moments with fast multipole acceleration and hybrid asymptotic methods for electrically large platforms.[1][2][3] Each suite now includes several solver types, so the choice often depends on workflow and problem size.
Which tool suits which problem?
| Problem | Commonly favored approach |
|---|---|
| Waveguide feeds, horns, filters, resonant structures | FEM (e.g., HFSS) |
| Wideband antennas, phones with many materials, transients | Time-domain FIT/FDTD (e.g., CST) |
| Antennas on vehicles, aircraft, ships; antenna placement | MoM/MLFMM and asymptotic hybrids (e.g., Feko) |
| Large finite arrays | Domain decomposition or periodic unit-cell plus finite-array methods |
Summarized from vendor documentation and the Antenna Engineering Handbook.[4]
What about cost and access?
Commercial solvers carry significant license costs; academic and startup programs exist. Free alternatives such as openEMS and NEC-2 cover many problems, and cross-checking a model between two solvers is a good practice.[5][6]
Frequently asked questions
Do I need a commercial solver to design a PCB antenna?
Not necessarily; copying a validated reference and tuning by measurement often suffices.
Which is most accurate?
All are accurate when converged; setup quality matters more than brand.
Can these tools optimize designs?
Yes, all include parametric sweeps and optimizers.
See also
References
Online sources accessed October 21, 2026; printed works cited by edition. See all sources.
- “Ansys HFSS (finite element method 3D electromagnetic simulator)”. Ansys, Inc.. product documentation.
- “CST Studio Suite (time-domain FIT and frequency-domain solvers)”. Dassault Systèmes. product documentation.
- “Altair Feko (method of moments and hybrid solvers)”. Altair Engineering. product documentation.
- “Antenna Engineering Handbook, 4th ed.”. J. L. Volakis (ed.), McGraw-Hill. 2007.
- “openEMS: a free and open electromagnetic field solver using the EC-FDTD method”. openEMS project. accessed October 2026.
- “Numerical Electromagnetics Code (NEC) — Method of Moments, Tech. Rep. UCID-18834”. G. J. Burke and A. J. Poggio, Lawrence Livermore Laboratory. January 1981.