A Compact Slotted Waveguide Array Antenna With a Cubic Post Radiator for Aerial Vehicle Applications

This study presents a compact high-gain antenna, designed to be mounted on unmanned aerial vehicles, for millimeter-wave band applications. This antenna combines a slotted waveguide array (SWA) with a cubic post radiator (CPR) for performance enhancement. By utilizing the CPR structure, the radiation of the SWA antenna can be effectively focused in a particular direction, resulting in improved gain, suppressed sidelobes, and enhanced aperture efficiency. The antenna design incorporates a
$10\times 10$
array with optimized parameters, along with a centralized double-layer feeding scheme that employs reflection-canceling steps. This feeding scheme improves the impedance bandwidth of the series feed. Consequently, the array antenna operates within an impedance bandwidth of 1.3 GHz, spanning from 26.5 to 27.8 GHz. The fabricated prototype exhibits a peak realized gain of 29.1 dBi and a sidelobe level of −14.6 dB at 26.9 GHz, with a gain variation within 2 dB across the entire operating band. Moreover, it achieves a maximum total efficiency of 95% and maximum aperture efficiency of 85%. In addition, the prototype antenna was tested on a drone, establishing a reliable wireless link between the airborne vehicle and ground station.