Hertzon

A free, open-source 3D full-wave electromagnetic simulator with a classic engineering workflow: draw the model, assign boundaries and ports, solve with adaptive meshing, then look at S-parameters, fields and radiation patterns. The finite-element solver underneath is EMerge (2nd-order Nédélec FEM).

Download for Windows / Linux Source code on GitHub Tutorial

What you can simulate

Antennas: patch and dipole antennas with far field, gain, directivity, beamwidth and 3D radiation patterns
Microwave circuits: microstrip lines and filters with S-parameters, Smith charts and frequency sweeps
Waveguides and coaxial lines: wave ports, modes and field plots
Radar cross section (RCS) with incident plane waves
PCB designs: Gerber export of the simulated layout

Why Hertzon

Finite-element method (FEM) frequency-domain solver with adaptive mesh refinement until S-parameters converge
Own mesher (hzmesh), curved elements, fast error estimator and faster assembly kernels on top of EMerge
Desktop GUI (Qt + VTK) that stays responsive with large models; the solver runs in its own process
Python scripting and an MCP server, so AI assistants can build and run simulations
Free and open source under the GPL, for Windows and Linux

Screenshots

Hertzon 3D modeler with a microwave structure — 3D modeler

3D gain pattern of a patch antenna simulated in Hertzon — 3D gain of a patch antenna

Radiation pattern plot of a patch antenna — Radiation pattern

Smith chart of simulated S-parameters — Smith chart

Electric field on a microstrip line — Fields on a microstrip line

S-parameter plot over frequency — S-parameters over frequency

Get started

Download the installer from the releases page, then follow the step-by-step tutorial: a waveguide with wave ports, a coaxial cable, a half-wave dipole and the RCS of a sphere, each from the empty window to the result. More: feature matrix, benchmarks, changelog.