Sma launch

kicad2ems

kicad2ems simulates KiCad boards. It reads the stackup, copper, vias and outline from a .kicad_pcb, takes ports from marker footprints and R/L/C parts from the components, and solves the board with one or more electromagnetic solvers. Each run writes Touchstone S-parameters, plots, a JSON summary and an HTML report that compares the solvers.

kicad2ems is the core: the board model, the line model, the settings, the runs and the results. The rest are packages of their own, each in its repository:

By default kicad2ems picks the full-wave solver it expects to be fastest for your board and adds the line model (which solver).

Gallery

The KiCad plugin beside KiCad 10's PCB editor with its CM5 Minima demo board: the HDMI D0 pair selected in KiCad, and the region and ports the plugin set up around it.

The impedance map of the board's 94 signal nets filling in; the HDMI pairs against their 100 ohm class, a section read out at the bottom; the D0 pair's mixed-mode S-parameters from gfdtd (solid) and the line model (dashed).

The same pair driven differentially from the module: its E field just inside the F.Cu and B.Cu dielectrics, in dB re the peak (30 dB range), from gfdtd's field dumps of the two legs' runs.

The E field of a 2.45 GHz patch antenna (--dump E@volume+12@2.45) and of a stub notch filter at its 2.4 GHz notch, over one period: the GUI's 3D field view, translucent over the copper.

A hairpin band-pass filter solved by gfdtd (FDTD), mom25d (MoM) and the line model (qucsator), overlaid in the GUI with a Smith chart.

Left: mom25d's surface current on the stub notch at 2.4 GHz (--mom-dump 2.4 --dump-animate gif): the quarter-wave stub holds the standing wave and nothing passes it. Right: the patch in antenna mode: match, gain and efficiency over frequency, polar cuts.

The hairpin's mom25d mesh in the Viewer's plan (rings of thin cells along the copper's edges), and the line sections the line model finds. kicad2ems-gui's tools/readme_media.py makes these pictures again from the examples; the plugin's were recorded from KiCad 10, driven by a script.

Features

• KiCad import (KiCad 5 to 10): stackup, tracks, arcs, zones, graphics, pads, vias and outline. Gerber files work too.
• Ports from footprints with a Fab text P1, P2, …, including differential pairs (P1+ / P1-) and gap ports for antennas.
• Lumped parts from two-pad R/L/C footprints.
• Antenna mode: gain, efficiency and radiation patterns; phased arrays steered after the run.
• Field dumps of E, H or current density: images, animations, and a 3D view.
• GUI (kicad2ems-gui) for setup, preview, progress and results.
• KiCad plugin (KiCad 9+, IPC API): the open board's trace impedances in the PCB editor, and a region with ports to simulate (KiCad plugin).
• GPU acceleration for gfdtd and mom25d: any GPU through Vulkan, or CuPy on CUDA or ROCm.
• Solver plugins: other solvers can be added as packages.

Install

Linux and macOS:

git clone https://github.com/lowprocess/kicad2ems.git && cd kicad2ems
./setup.sh
source .venv/bin/activate

Windows (Python 3.10 or newer from python.org, and Git):

git clone https://github.com/lowprocess/kicad2ems.git && cd kicad2ems
py install.py
.venv\Scripts\activate

The installer (install.py; ./setup.sh runs it) asks where to install (a venv in this checkout by default, or for your user, system-wide, or into the Python itself) and which optional parts you want: the GUI, the solvers and their compiled cores, a GPU package, openEMS, qucsator and a launcher entry. --yes takes the defaults. Getting started has the options and installing by hand. Without any full-wave solver, kicad2ems runs the line model alone; kicad2ems --check shows what your setup can run.

Quick start

kicad2ems examples/rf_interdig.toml --preview            # model, mesh and line model only: seconds
kicad2ems examples/rf_interdig.toml --solvers mom,lines  # MoM and the line model: about a minute
kicad2ems examples/rf_interdig.toml --solvers all        # every solver, compared

Results go to examples/out/: filter_<solver>.s2p for each solver, plots, filter_run.json and filter_report.html. To simulate your own board, see Getting started.

Documentation

Start with Getting started, then Usage. The documentation index lists every page.

License

GPL-3.0-or-later (see LICENSE). kicad2ems uses openEMS (GPL-3.0-or-later) and CSXCAD (LGPL-3.0-or-later) as Python packages and runs qucsator (GPL-2.0-or-later) as a separate program. No third-party code is copied into the repository.