AntennaKNoBs

New in v0.46.0

The engine-for-hire release: momwire now runs inside SimNEC. Point SimNEC’s NEC-portal dialog at the new momwire-nec2c drop-in and its Smith chart, tuners, and sweeps run on momwire’s solver — no change to SimNEC needed. The protocol was reverse-engineered against SimNEC’s own bundled engine (40 captured printout pairs, reproduced column-for-column) and then validated in a live SimNEC session: a real station circuit within a few percent through a high-Q tuner, pattern levels agreeing to ~0.01 dB, and SimNEC’s own 4-source phased-array example matching to 1 Ω of reactance. A --basis flag picks the physics from the portal dialog itself — paste two entries and you have cross-basis validation inside SimNEC, with sinusoidal-galerkin-converged on call for near-open high-Q feeds. Structurally faster where it counts: N-port probes cost one matrix fill, not N. Plus: multi-feed `.ssn` exports now refuse rather than silently losing their drive phasing. Start at Using momwire as SimNEC’s engine.

The whole pitch, in one line

antennaknobs describes an antenna as Python code — a small parametric builder, its geometry computed from named knobs — then lets you explore it two ways: drive it from a script (sweep, optimize, compare, export a NEC deck), or open it in a browser and turn the knobs live, watching the radiation pattern, SWR, and impedance respond as you drag. Most antenna tools are a static formula calculator or a desktop app you have to install; this is neither.

Antennas as Python code

Describe an antenna once as a small parametric builder — geometry computed from named knobs — then sweep, optimize, compare, or open it in the browser. Most tools make you hand-place every coordinate.

Multi-basis MoM

Sinusoidal and B-spline bases in one engine, cross-validating each other — basis quality that otherwise costs four figures in commercial tools.

Fast on big arrays

H-matrix / ACA acceleration with GMRES, where every free NEC tool is dense O(N²). Demonstrated O(N log N) on a 2142-segment Yagi.

Cross-checked physics

A NEC-2 reference engine runs alongside the in-house solver, so you get a built-in accuracy check most tools lack.

No platform lock-in

A web UI by default — works anywhere a browser does, while the competition is Windows/Linux/macOS desktop-only or a GUI-less library.

Start here

What is antennaknobs? The tool, who it's for, and how the pieces fit.

Quickstart pip install, then a resonant dipole in ten lines of Python.

Many ways to express geometry The same delta loop, one knob-set, built four different ways — pick the one that fits how you think.

The solver & accuracy Bases, H-matrix acceleration, and how it's validated.