Introducing simpleEMS — a Python framework for antenna & RF design built on openEMS

[MohamoudAli12]

Hi everyone,

I'd like to introduce simpleEMS, an open-source Python library built on top of openEMS that aims to make antenna and microwave structure design, simulation, optimization, and visualization dramatically simpler — without giving up the power of a real FDTD engine.

What simpleEMS gives you

Parametric structure builders

• Inset-fed patch antenna
• Probe-fed patch antenna
• Microstrip line
• Bandpass quarter-wave stub filter
• Bandstop quarter-wave stub filter

Each is a small, typed parameter object (dimensions, substrate, feed geometry, frequency) that generates the CSXCAD geometry, ports, and mesh for you — no need to hand-write FDTD boilerplate for common structures.

Simulation & optimization

• Parameter sweeps over any design variable
• S11 / S21 / combined S-parameter optimization

Network parameter calculation: S11, S21, VSWR, Z11, input power

Visualization: S11/S21/VSWR plots, Smith chart, complex Z11 plots, 2D radiation pattern & directivity, 3D radiation pattern/gain/power plots

Field dumps for ParaView: E-field and H-field (time & frequency domain), current density (time & frequency domain)

Export options: Gerber (fab), STEP/STL (3D geometry), Touchstone (.sNp)

Batteries-included CLI: simpleems checkhealth verifies your Python and system dependencies, and simpleems install openems automates installing openEMS itself on all platforms.

I think the one functionality that you will love is that you can simulate your existing openEMS models using simulate_model function, you can read further in the standalone model tutorial.

Status

v0.1.0 (initial public release), Still early — APIs may shift — but the antenna/filter builders, simulation pipeline, plotting/export suite, and optimization tools work end-to-end.

Demo

The README walks through building and simulating a 2.45 GHz inset-fed patch antenna in a handful of lines, auto-generating geometry preview, S11, Smith chart, Z11, VSWR, and 2D/3D radiation pattern plots.

I'd love feedback from this community.

The project is available on PyPi you can easily install it with pip install simpleEMS.

for further reading please refer to the docs

[fidel-071223]

Nice. Install went fine on Mac. On Windows it needs Python 3.13 to work with the latest openEMS version 0.37RC2

[MohamoudAli12]

Thanks @fidel-071223. I don't have access to a Mac, so it is good to know that it works in there.
On Windows, I also noticed some versions of openEMS don't work and will throw "Attribute" error.
did you manually install openEMS on Mac and Windows or did you use the simpleems cli?

[fidel-071223]

I did manual installs for both. I see you updated to 0.4 version, nice fix to IFAAntenna from 0.3 version. I also updated my openEMS to RC3 and it worked fine on transmission line and IFA antenna at 2.4 GHz, nice 3D directivity and gain plots.
@MohamoudAli12 As said, IFA example at 2400 MHz is right on the money, but I see an issue on IFA where I changed the F0=5210MHz, and simpleEMS failed to build the proper lengths, Zin is 140 Ohm instead of 50. Will try to comment on your git repo in the future.

[MohamoudAli12]

@fidel-071223 thanks, I see the issue. I have a solution for it. Please make an issue in the git repo and I will share it there with you.