How do you get accurate antenna simulations?
Accurate antenna simulation depends more on setup than on solver choice: define ports that represent the real feed, converge the mesh, keep boundaries far enough away, use correct material data at the operating frequency, include the environment (ground plane, enclosure, cables, hands) and validate against a canonical case and measurement.[1][2][3]
How should ports be modeled?
Use waveguide or wave ports for coax and transmission-line feeds where the field pattern is known; lumped ports only across gaps small compared with λ. Port location should match where the VNA reference plane will be in measurements, or de-embed accordingly.[2][4]
How do you check convergence?
Refine the mesh (or reduce cell size) until resonant frequency and S11 change by less than the required tolerance, typically well under 1%. In FEM, monitor adaptive pass convergence; in FDTD, check energy decay to −40 to −60 dB before ending the run.[1][2]
What common mistakes should be avoided?
- Boundaries too close (less than about λ/4 from radiators at the lowest frequency).
- Using nominal FR-4 εr without loss tangent or frequency dependence.
- Omitting the enclosure, battery, display or coax cable.
- Infinitely thin perfect conductors where conductor loss matters (small antennas).
- Trusting a single run without a sanity check such as the efficiency or average gain test.[5][3]
Frequently asked questions
How close can boundaries be?
Absorbing boundaries are commonly placed at least λ/4 from radiating parts; PML can be closer per solver guidance.
Should I simulate the cable?
For small antennas yes, or model a choke, because cable currents change results.
How close should simulation and measurement agree?
Resonance within a few percent and efficiency within about 1 dB is a common target for embedded antennas.
See also
References
Online sources accessed October 21, 2026; printed works cited by edition. See all sources.
- “Computational Electrodynamics: The Finite-Difference Time-Domain Method, 3rd ed.”. A. Taflove and S. C. Hagness, Artech House. 2005.
- “The Finite Element Method in Electromagnetics, 3rd ed.”. J.-M. Jin, Wiley. 2014.
- “Antenna Engineering Handbook, 4th ed.”. J. L. Volakis (ed.), McGraw-Hill. 2007.
- “Applying Error Correction to Network Analyzer Measurements (Application Note 1287-3)”. Keysight Technologies. application note.
- “Numerical Electromagnetics Code (NEC) — Method of Moments, Tech. Rep. UCID-18834”. G. J. Burke and A. J. Poggio, Lawrence Livermore Laboratory. January 1981.