A Quad-Polarization Reconfigurable Conformal Array of Wide Coverage Range and High Gain for Unmanned Aerial Vehicle Communications

This communication presents a quad-polarization reconfigurable multifaceted conformal array of wide coverage range and high gain that is suitable for unmanned aerial vehicle (UAV) communication applications. The design features a sparse array layout comprised of three conformal subarrays, where each subarray includes nine quad-polarization reconfigurable radiating elements. The radiating element is a single-port excited patch radiator loaded by edge slots for size miniaturization and central shorting pin for biasing simplification, which is integrated with a low-complicity reconfigurable feeding network consisting of relatively few PIN-diodes and biasing lines. Using such a miniaturized and high-efficiency element, a polarization reconfigurable conformal array prototype is designed, fabricated, and experimentally characterized. Simulation and measurement results have shown that the presented conformal array exhibits a 3 dB axial-ratio (AR) bandwidth of up to 1.3% at around 1.5 GHz and -10 dB impedance bandwidth of 7.7% for two circular-polarization modes and 7.3% for two linear-polarization modes, respectively. Besides, the realized gain is over 14 dBi for all reconfigurable polarization modes over a relatively wide beam coverage range of 50 degrees x 180 degrees.