Circularly polarized High-Gain Antenna for Long-Range UAV Communication

This paper proposes unified intelligent high-gain antenna architecture for long-range unmanned aerial vehicle (UAV) air-to-ground (ATG) communication, co-designing a reconfigurable circularly polarized (CP) microstrip antenna front-end. The antenna element utilizes a high-order resonant mode of the substrate integrated waveguide (SIW) cavity structure to realize the simultaneous improvement of gain and front-to-back ratio (FBR), effectively eliminating the inherent back-lobe radiation of the patch antenna over the UAV platform. The proposed system demonstrates the achievement of the desired operational bandwidth of 5.43–5.48 GHz, the maximum realized gain of 12 dBi, and the FBR greater than 21 dB across the entire bandwidth.