Our application of FDTD to challenging antennas is founded on three decades of defense industry work. The methodology lives in an independently developed MRS toolchain — purpose-built for the problems we solve daily, including fragmented aperture optimization, phased-array element design, and platform RCS studies. We're publishing it in stages: a public alpha of the geometry viewer is available below, with the FDTD core and remaining GUI tools to follow as they harden.
The MRS toolchain
Five tools, two layers. The openTDA solver does the physics; the GUI tools wrap it for everyday engineering work; the matching tools are standalone utilities for RF circuit design.
openTDA — proprietary FDTD solver
A full-wave 3D finite-difference time-domain electromagnetic solver, built at MRS on a foundation of 30+ years of FDTD experience. openTDA handles broadband antenna analysis, radar cross section, conformal and dispersive media, and large-scale platform integration. The solver underpins every fragmented aperture design we've ever shipped.
Status: Internal — public release under evaluation.
OpenResults — results viewer
The post-processing GUI for openTDA. Plot S-parameters, gain patterns, current distributions, near-field cuts, and time-domain waveforms from solver output files. Built for engineers who want to interrogate a simulation, not just look at headline numbers.
Status: Internal — alpha planned.
OpenDXF — geometry viewer
A 3D DXF geometry viewer for inspecting antenna and platform models before and after they go into the FDTD grid. Rotate, pan, zoom, and step through layer structure interactively. The first MRS tool released publicly — alpha is available for download below.
Status: Public alpha — available below.
openSmith — Smith chart workbench
An interactive Smith chart utility for impedance matching, network synthesis, and tuning studies. Drag lumped or distributed elements, watch the trajectory update live, and export a netlist when the match is where you want it.
Status: Internal — public release under evaluation.
openMatch — automated matching-network synthesis
Given a measured or simulated impedance trace and a target return loss across a frequency band, openMatch searches lumped-element topologies and returns ranked candidate networks with predicted performance. Pairs with openSmith for hand tuning and with openTDA for full-wave verification — the same workflow we use on client matching-network engagements.
Status: Internal — public release under evaluation.
Available now: OpenDXF (openTDA Viewer) alpha
The first public release from the MRS toolchain. OpenDXF — packaged as "openTDA Viewer" in the
installer — is a 3D DXF geometry viewer for engineers and technical users. Open a .dxf
file and explore the geometry interactively: rotate, pan, zoom, and inspect layer structure.
Built with VTK and PyQt6.
This is an early alpha release. It is functional but rough around the edges. We are sharing it now to collect real-world feedback before further development. All platforms — macOS, Windows, and Linux — are supported.
Download — openTDA Viewer v0.3.1
Heads up: These files are 150–260 MB. After clicking a download button, your browser may appear to do nothing for several seconds before the download begins — that's normal. Please be patient and do not click again.
macOS
Note: This build is not code-signed. On first launch, right-click the app and choose Open to bypass Gatekeeper.
Windows
Note: Windows SmartScreen may warn on first run. Click More info then Run anyway.
Linux
.deb: sudo dpkg -i openTDA_Viewer-0.3.1-amd64.deb
AppImage: chmod +x openTDA_Viewer-0.3.1-x86_64.AppImage && ./openTDA_Viewer-0.3.1-x86_64.AppImage
Why build our own tools?
Commercial EM solvers are excellent general-purpose products, but the problems we work on — fragmented aperture optimization, ultra-wideband phased arrays, AI-accelerated EM surrogates — live at the edge of what those packages do well. Owning the solver lets us instrument it, extend it, and tune it to the physics of each engagement. It's also how we deliver results faster than a typical commercial-tool workflow: when the question is unusual, we can change the code instead of working around it.
Releasing portions of the stack publicly serves two purposes. First, it gives the broader antenna and CEM community useful, free utilities. Second, it surfaces bugs and feature requests from real users — the kind of feedback you can't get from internal use alone. If you try the OpenDXF alpha and have thoughts, we want to hear them.
Send us your feedback
What works? What doesn't? What would you like to see next? All feedback — bugs, feature requests, and general impressions — is welcome and appreciated. If a particular tool from the toolchain above would make your work easier and you'd like us to prioritize it, tell us that too.