Conformal Subarray Antenna for Circularly Polarized Synthetic Aperture Radar onboard UAV

This paper presents a preliminary design of a conformal subarray antenna for circularly polarized synthetic aperture radar (CP-SAR) onboard UAV. The CP-SAR is operated in C-band with the center frequency of 5.3 GHz and bandwidth of 400 MHz. Limitation space inside the fuselage and the CP-SAR signal attenuation issue caused by the fuselage material will be attempted to overcome by installing a conformal CP-SAR antenna wrap-around outside the UAV fuselage. An osculating circle with a radius curvature of 920 mm is used to reference fuselage curvature to bend the antenna. Simulation results show the conformal antenna achieves excellent performance characteristics. The antenna is currently fabricated and will be validated in the next work.