Cylindrical-Wave Linear-Array RCS Measurement: Quiet-Zone Design, Aperture Utilization, and Experimental Comparison with a Compact Range

Low-frequency radar cross-section (RCS) illumination requires a balance between aperture length, directional field variation, and source placement. This engineering study reanalyzes section-level field summaries and compares archived HH target records with analytical sphere responses and compact-range measurements. A 0.3–1.0 GHz length sweep covers five longitudinal sections of a nominal cylindrical envelope with 20 m horizontal diameter and 5 m height. Increasing array length from 10 to 12.5 and 15 m reduces the maximum reported amplitude span from 3.086 to 2.319 and 1.010 dB. Additional aperture improves low-frequency vertical profiles, while the serrated reflector has smaller central horizontal spans. The present 40-element shared-chamber layout is distinguished from the supporting 32-element target records. Reported sphere RMS discrepancies from monostatic Mie references are 0.55–0.72 dB; the cylinder-to-compact-range RMS difference is 1.31 dB at 0.5 GHz. A generic model with approximately 1.5 m wingspan supports qualitative angular-pattern comparison. Together, the records identify aperture-length tradeoffs within their stated profile and HH measurement scope.