FULL-WAVE gerber'd quasi-Yagi pair (uploaded-Gerber element), mechanically joined by TWO identical 12 mm × 2 mm FR4 backing splice strips on the voltage-null lines (coplanar_monopulse_linked convention), lengthened to CROSS each board's boom for a solid connection (RF-negligible): REAR across the reflectors and FRONT across the boom spine BETWEEN dir-1 and dir-2 — longitudinal field minima, off every element tip and the feed slot, so they barely move resonance/gain yet deepen the Δ null to ≈−28…−34 dB (vs −21…−25 dB unlinked), re-simulated at 0.5λ (163.9 mm) · rotating monopulse, 100 readings/° · 1 dB steps · 3 dB noise → σ_eff 0.30 dB/° · Σ HPBW 44° · Σ F/B 7.5 dB · Δ null −27.6 dB · single-emitter ACCURACY 0.14° (1σ) · two-emitter RESOLUTION 5.3° (1-source goodness-of-fit, WORST case for unequal emitters within 5 dB) · NOTE: at 0.5λ the element's 179 mm reflectors just touch/merge — the rear back-tie strip splices the two boards into one rigid panel exactly where the reflectors meet · resolution-vs-spacing = shape-preserving interpolation through 11 full-wave anchors, same design-level curve as the other cards; F/B in the 0.5–0.6λ band peaks at 8.6 dB @ 0.60λ · the u=Σ−Δ scan also reads an unequal pair's power ratio via a 2-source fit (CENTRE free + floor from the ROTATION MINIMUM): at a resolved 20° split → ratio 5.1±0.3 dB, centre ±0.4°, floor ±0.1 dB
⬗ stack-up: FR4 1.6 mm (εr 4.3) · 1 oz Cu (35 µm) · single layer · 2× 2 mm FR4 back-tie splice strips · 2-element Σ/Δ @ 163.9 mm (0.5λ)