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https://github.com/NawfalMotii79/PLFM_RADAR.git
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Jason
3f3846b514
Single-element OpenEMS sim for a 2-layer probe-fed patch on 0.508 mm RO4350B. Verified at PROFILE=balanced (λ/25 mesh): f_res = 10.51 GHz, S11 = -21.8 dB, VSWR 1.18, -10 dB BW = 180 MHz (10.40-10.58 GHz). Direct 50 Ω match — no port matching cap needed. Design point baked into defaults: PATCH_W = 7.854 mm (preserved from old 8x16 Gerber → array compatible) PATCH_L = 6.56 mm (tuned for f_res = 10.5 GHz at 0.508 mm sub) FEED_OFFSET = 2.14 mm (probe via, from -y radiating edge) Why probe-fed: aperture-coupled v2 (4-layer Stack_Hybrid) capped at ~60 MHz BW because the 0.11 mm L4 acts as a near-short reflector — beneficial for slot coupling but creates an L2-L4 cavity that's the BW ceiling. Tested removing L4 (open-back aperture-coupled): coupling collapsed, R stayed >1000 Ω regardless of patch tuning. Probe-fed has no slot bottleneck; physics BW = 1.7% on h=0.508 matches sim 180 MHz directly. Hardware change required to deploy: 2-layer stackup (patch on top, ground on bottom, probe vias with antipads). Old 8x16 Gerber was edge-fed; v3 is probe- fed → top-layer feed network goes away, ADAR1000 carrier on a separate board with SMP RF launches. Stackup signoff with antenna designer needed before PCB. aperture_coupled_v2 retained as the 4-layer fallback (with the 0.043 pF cap) if 2-layer redesign isn't approved.
