A Compact Multitaper Conical Spiral Sensor With Stable Field of View for UAV Integrated Sensing and Communication

Compact UAV-based integrated sensing and communication (ISAC) systems require broadband front-ends with stable radiation characteristics. Conventional wideband conical spirals often suffer from beam splitting and unstable field-of-view (FoV) at high frequencies, leading to coverage blind spots. To address this, a compact wideband conical spiral sensor optimized for continuous wide-angle coverage is proposed. By employing a phase-velocity-compensated multi-section tapered profile, the design suppresses high-frequency parasitic modes to ensure a consistent spatial response. Measurement results demonstrate a 15:1 bandwidth (1.2–18 GHz) with high-purity left-hand circular polarization (LHCP) and a stable instantaneous field of view (iFoV) of 70°–100°, validating the elimination of coverage gaps observed in standard designs. System-level validation through tethered UAV flight trials verifies reliable signal reception at 17.5 GHz, maintaining stable received power levels even during platform banking maneuvers. The sensor provides quasi-omnidirectional coverage in lower bands and wide-beam directional sensing in upper bands, making it a suitable solution for high-probability-of-intercept (HPoI) airborne nodes.