Loaded Disc Feeding Method for Radial Line Slot Antennas

Abstract

This paper presents a multi-band parametric sensitivity study of the loaded disc feeding method for Radial Line Slot Antennas (RLSAs). Using full-wave simulations from 10-20 GHz, we quantify how three manufacturable dimensions-air gap below the disc, head-disk thickness, and head-disk diameter-govern input match sensitivity. A clear, frequency-aware sensitivity hierarchy emerges: the air gap is the principal driver at mid-to-high bands, peaking at 6.50 dB/mm at 12.5 GHz and remaining high (4.18-5.22 dB/mm) up to 20 GHz; at 10 GHz, head-disk thickness dominates (3.83 dB/mm), while the air gap weakens (1.51 dB/mm). By contrast, head-disk diameter is consistently benign (0.03-0.41 dB/mm), enabling relaxed tolerances. These results translate into concrete, band-specific tolerance allocations: tighten the air gap assembly at 12.5-20 GHz, prioritize thickness at 10 GHz, and apply standard machining to the diameter. The proposed sensitivity framework provides actionable guidance for robust, cost-effective RLSA manufacturing without sacrificing performance. © 2025 IEEE.