From abc7e3c66b3e44af7f2f7b66465873a2aab9f4a9 Mon Sep 17 00:00:00 2001 From: Jason <83615043+JJassonn69@users.noreply.github.com> Date: Mon, 4 May 2026 00:41:28 +0545 Subject: [PATCH] sim(antenna): center 1x8 row dip on radar TX 10.520 GHz (CONN_LEN 8.0->8.15) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sweep CONN_LEN at PROFILE=balanced to land the operating-mode dip on the chirp-band center instead of 60 MHz above it. Sensitivity is df/dCONN ≈ -0.20 GHz/mm (longer line → lower op freq). CONN=8.00 → dip 10.560 GHz, S11@10.520 = -12.6 dB (above TX) CONN=8.15 → dip 10.520 GHz, S11@10.520 = -18.8 dB (TX-centered) CONN=8.20 → dip 10.510 GHz, S11@10.510 = -18.4 dB (TX low edge) CONN=8.25 → dip 10.500 GHz, S11@10.500 = -18.4 dB (LO-centered) CONN_LEN=8.15 wins because the radar TX 10.510-10.530 GHz sees -17 to -19 dB symmetrically across the band, with -15 dB margin at the LO frequency. -10 dB BW spans 10.470-10.580 GHz (110 MHz). Pitch 15.10 mm vs old Gerber 15.01 mm. --- .../Antenna/edge_fed_row_aeris10_v3.py | 27 ++++++++++++------- 1 file changed, 17 insertions(+), 10 deletions(-) diff --git a/5_Simulations/Antenna/edge_fed_row_aeris10_v3.py b/5_Simulations/Antenna/edge_fed_row_aeris10_v3.py index 16bfd6c..0df6803 100644 --- a/5_Simulations/Antenna/edge_fed_row_aeris10_v3.py +++ b/5_Simulations/Antenna/edge_fed_row_aeris10_v3.py @@ -17,16 +17,24 @@ # top-below-stopband mode (deepest dip just below the gap center). # # Verified design point (PROFILE=balanced, λ/25 mesh): -# W=7.854 mm L=6.95 mm CONN_LEN=8.0 mm pitch=14.95 mm +# W=7.854 mm L=6.95 mm CONN_LEN=8.15 mm pitch=15.10 mm # INSET_DEPTH=0 (direct edge feed; inset on patch 0 drops Z to ~6 Ω which # is unmatchable for N=8 — natural edge-fed Z at array resonance is ~80 Ω, # close to 50 Ω so no input matching network is needed) # FEED_W=1.16 mm FEED_LEAD=15.5 mm # -# Verified result: -# Top-below-gap mode at 10.56 GHz: S11 = -22.5 dB, Zin = 79.9 - j3.3 Ω -# -10 dB BW: 100 MHz (10.510 - 10.610 GHz) -# Covers radar TX 10.510-10.530 GHz with S11 = -10.9 to -14.6 dB +# Verified result (operating-mode CONN_LEN swept to land dip on TX center): +# Operating mode at 10.520 GHz: S11 = -18.8 dB, Zin = 76.2 - j9.3 Ω +# -10 dB BW: 100 MHz (10.470 - 10.570 GHz) +# Across radar TX 10.510-10.530 GHz: S11 = -17.4 to -18.8 dB (symmetric) +# At 10.500 GHz (LO): S11 = -15.4 dB +# +# Sensitivity: df/dCONN_LEN ≈ -0.20 GHz/mm (longer CONN → lower op freq). +# To recenter on a different freq: +# CONN=8.25 → dip at 10.500 GHz (LO-centered, TX edge falls off) +# CONN=8.15 → dip at 10.520 GHz (TX-centered, recommended) +# CONN=8.20 → dip at 10.510 GHz (TX-low-edge centered) +# CONN=8.00 → dip at 10.560 GHz (above TX band) # # CRITICAL difference from edge_fed_aeris10_v3.py: single-element used inset # (INSET_DEPTH=3.40) to match each patch to 50 Ω; row uses NO inset because @@ -105,11 +113,10 @@ INSET_DEPTH = float(os.environ.get("INSET_DEPTH_MM", "0.0")) INSET_GAP = float(os.environ.get("INSET_GAP_MM", "0.30")) FEED_LEAD_L = float(os.environ.get("FEED_LEAD_MM", "15.5")) -# Connecting line. With CONN_LEN=8.0 the array's stopband is centered on the -# patch resonance (~10.5 GHz for L=6.95) and the deepest below-gap mode lands -# at 10.56 GHz, with -10 dB BW spanning 10.51-10.61 GHz (covers radar TX -# 10.510-10.530). Pitch = PATCH_L + CONN_LEN = 14.95 mm matches old Gerber. -CONN_LEN = float(os.environ.get("CONN_LEN_MM", "8.0")) +# Connecting line. CONN_LEN=8.15 lands the operating-mode dip at 10.520 GHz +# (radar TX center), giving symmetric -17 to -19 dB across the 10.510-10.530 +# chirp band. Pitch = PATCH_L + CONN_LEN = 15.10 mm (vs old Gerber 15.01). +CONN_LEN = float(os.environ.get("CONN_LEN_MM", "8.15")) PITCH = PATCH_L + CONN_LEN