Low-Profile All-Metal Dual-Band Dual-Polarized Shared-Aperture Phased Arrays for UAV Applications

A low-profile, all-metal, dual-band, dual-polarized shared-aperture phased array (SAPA) is proposed for UAV radar systems. The phased array element consists of a semi-open stepped radiating slot loaded with a pair of metal ridges to achieve the desired small aperture, wide beam, and low cross-polarization properties. Compared with traditional all-metal phased array element, the antenna profile can be reduced while not compromising radiation characteristics. Based on this element, a single-polarized phased array and two dual-polarized SAPAs with different frequency ratio have been developed. By adjusting the spacing between the dual ridges of the elements, the frequency ratio of the dual-band dual-polarized SAPA can be flexibly controlled ranging from 1:1 to 3:1. To validate this concept, a prototype of the SAPA operating in the S-band and C-band was fabricated and measured. The measured results demonstrate a beam scanning range of ± 60° in the dual-band range with a gain drop of within 5.5 dB. The proposed SAPA represents a promise candidate for UAV radar systems that facilitate communication within the Internet of Vehicles.