PCB RF Shielding-Can Internal Cavity Resonance, Via-Fence Pitch & Vent-Slot Cutoff Solver

Deterministic Rectangular metallic cavity eigenvalue spectrum f_mnl = (c/(2*sqrt(eps_r)))*sqrt((m/a)^2 + (n/b)^2 + (l/d)^2) + slot/aperture waveguide-beyond-cutoff SE = 20*log10(lambda / (2*L_slot)) engine (.json, .csv, .dxf) built for Laird Performance Materials, Würth Elektronik, Harwin, Masach Tech — zero-upload ephemeral Wasm RAM execution.