Statistical resolution limit (SRL) — closest two targets tellable apart vs SNR · hover a point (session 014z DF model)
Σ 11.0 dBi (+2.9 dB array) · Σ F/B 12.7 dB (= element F/B — the sum adds gain, not F/B; the pair beats the single element's 9.3 dB via reflector mutual coupling, NOT the sum) · Δ null −35 dB · ±28° Δ lobes · res 915 MHz (S11 −33 dB) · 240 mm (0.73λ) · TWO IDENTICAL 4 mm FR4 links (12×252 mm) glued to the board UNDERSIDE (rear across the reflectors + front across the boom spines) — FDTD(PML_8)-verified benign: Δf_res 0 MHz, ΔΣ-peak −0.06 dB, ΔΔ-null −0.2 dB · l_drv 130.5 (PML-tuned: the pair resonates ~22 MHz below the single because the two large reflectors couple) · links land on the reflector/boom-spine voltage nulls, clear of element tips & the feed slot · 1 layer slotline balun · ideal coupler · PML_8 (accurate gain)
⬗ stack-up: FR4 1.6 mm (εr 4.3) · 1 oz Cu (35 µm) · single top layer, ribbed · 2× 4 mm FR4 ties (12×252 mm) glued underneath