When and how should EM simulation be used?

From RF Design Wiki · By the RF Design Wiki editorial team · Published October 21, 2026 · Last reviewed October 21, 2026 · How we research

EM simulation solves Maxwell’s equations for a specific geometry to obtain S-parameters, fields and radiation. 2.5D planar solvers (usually method of moments) efficiently model layered PCB and IC metallization; 3D solvers (finite element, FDTD, finite integration) handle arbitrary structures such as connectors, packages, vias, enclosures and antennas.^[1]^[2]

What should be EM simulated?

Distributed filters, couplers and baluns.
Connector launches, via transitions, IC pad and package interfaces.
Antennas and their interaction with the enclosure.
Long or closely spaced lines where coupling matters.
Shield cans and enclosures for cavity resonances.

What setup mistakes are common?

Port definitions that do not match the real excitation (wrong reference, missing de-embedding).
Mesh too coarse at edges where current crowds; always run a convergence check.
Wrong material data (Dk/Df at the wrong frequency, no roughness model).
Boundaries too close to radiating structures.
Simulating only to the operating frequency and missing out-of-band resonances.

How are results validated?

Compare with closed-form results for simple structures, check passivity and reciprocity, compare different solvers on a critical structure, and correlate with measurements of test coupons.

Frequently asked questions

Is 2.5D enough for PCBs?

Often, for planar structures; vias, connectors and enclosures may need 3D.

How long do EM simulations take?

From seconds to hours or days depending on size and complexity.

Do EM results include losses?

Yes, if conductor and dielectric losses are defined correctly.

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.
“Numerical Solution of Initial Boundary Value Problems Involving Maxwell's Equations in Isotropic Media”. K. S. Yee, IEEE Transactions on Antennas and Propagation, vol. 14, no. 3, pp. 302-307. May 1966.

Categories: Simulation

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