How are antennas simulated?
Antennas are simulated with full-wave electromagnetic solvers based mainly on three methods: the method of moments (MoM), which solves integral equations for surface or wire currents; the finite element method (FEM), which solves the differential equations in a meshed volume in the frequency domain; and the finite-difference time-domain method (FDTD), which marches fields on a grid in time.[1][2][3] The best choice depends on geometry, materials and bandwidth.
How do the methods compare?
| Method | Unknowns | Strengths | Typical tools |
|---|---|---|---|
| MoM | Currents on wires/surfaces | Wire antennas, large metallic structures, open regions handled exactly | NEC, Feko[4][5] |
| FEM | Fields in a volume (tetrahedra) | Complex dielectrics, conformal geometry, high accuracy at a frequency | HFSS[6] |
| FDTD / FIT | Fields on a grid in time | Wideband response in one run, large inhomogeneous models, transients | openEMS, CST time domain[7][8] |
Which method should you use?
- Wire antennas (dipoles, Yagis, verticals over ground): NEC-type MoM.
- Printed antennas on layered substrates: planar MoM or FEM/FDTD.
- Antennas in phones with plastics, batteries and tissue: FDTD/FIT or FEM.
- Antennas on aircraft, ships or vehicles: MoM accelerated with fast multipole methods, or asymptotic hybrids.
- Ultra-wideband transient behavior: time-domain methods.[9]
How do you trust a simulation?
Check mesh convergence, boundary distance, port definition and material data; reproduce a canonical case such as a half-wave dipole (≈ 73 Ω, 2.15 dBi) first; and validate against measurement. See simulation best practices.[3][2]
Frequently asked questions
Is a free solver good enough?
For many problems yes: NEC-2 for wires and openEMS for 3D structures are widely used.
Do all solvers agree?
Well-converged models of the same geometry should agree closely; disagreements usually reveal setup differences.
What does a solver output?
S-parameters, impedance, current distributions, near fields and far-field patterns, gain and efficiency.
See also
References
Online sources accessed October 21, 2026; printed works cited by edition. See all sources.
- “Field Computation by Moment Methods”. R. F. Harrington, Macmillan (IEEE Press reprint 1993). 1968.
- “The Finite Element Method in Electromagnetics, 3rd ed.”. J.-M. Jin, Wiley. 2014.
- “Computational Electrodynamics: The Finite-Difference Time-Domain Method, 3rd ed.”. A. Taflove and S. C. Hagness, Artech House. 2005.
- “Numerical Electromagnetics Code (NEC) — Method of Moments, Tech. Rep. UCID-18834”. G. J. Burke and A. J. Poggio, Lawrence Livermore Laboratory. January 1981.
- “Altair Feko (method of moments and hybrid solvers)”. Altair Engineering. product documentation.
- “Ansys HFSS (finite element method 3D electromagnetic simulator)”. Ansys, Inc.. product documentation.
- “openEMS: a free and open electromagnetic field solver using the EC-FDTD method”. openEMS project. accessed October 2026.
- “CST Studio Suite (time-domain FIT and frequency-domain solvers)”. Dassault Systèmes. product documentation.
- “Antenna Engineering Handbook, 4th ed.”. J. L. Volakis (ed.), McGraw-Hill. 2007.