Validates the "Option C" hardware path: keep the old 8x16 Gerber's series-fed
edge-fed topology, just thicken the patch substrate from 0.102 mm to 0.508 mm
RO4350B. Single-element edge-fed with inset notch matched to 50 Ω microstrip.
Verified at PROFILE=balanced (λ/25 mesh):
W = 7.854 mm (preserved from old Gerber → array compatible)
L = 6.95 mm (tuned for f_res = 10.5 GHz on 0.508 mm sub)
inset_depth = 3.40 mm (~49 % of L)
inset_gap = 0.30 mm (each side of feed line, in the inset notch)
feed_W = 1.16 mm (50 Ω microstrip on 0.508 mm RO4350B)
feed_lead = 15.5 mm (= 1·λ_g at 10.5 GHz → port sees true antenna Z)
Result:
f_res = 10.509 GHz, S11 @ 10.5 = -18.5 dB, VSWR = 1.27
Z @ 10.5 = 61.8 + j3.2 Ω
-10 dB BW = 180 MHz (10.41-10.59 GHz, 1.71 %)
This is identical BW to probe_fed_v3 — confirming BW is set by substrate
thickness alone, not feed method. Edge-fed Option C is therefore the simpler
2-layer hardware path: same series-fed-row architecture as the old Gerber,
single PCB stackup, no probe vias / antipads / back-board splitter complexity.
Next step: extend to a 1x8 series-fed row to verify the daisy-chain topology
still gives in-phase feeding at the new substrate's λ_g.
Jason