Wideband Ridged Waveguide Slot Array Antenna with Low Cross-Polarization for Satellite Communications

In this paper, we present a new wideband slot array antenna based on rectangular ridged waveguide designed for satellite communications. The implementation of a rectangular ridged waveguide serves to minimize the overall volume of the antenna. Additionally, V-shaped slots integrated onto the ridged waveguide effectively reduce cross-polarization levels, achieving a horizontal polarization and the cross-polarization levels are less than -45 dB across wide radiation directions. The array element comprises 1 × 16 V-shaped slots. To feed these slots, a 1 to 2 waveguide power divider and two H-shaped coupling slots are employed, ensuring stable radiation patterns throughout the operating band. A prototype of the array is fabricated and subsequently measured. Both experimental and simulated results exhibit strong agreement, affirming the antenna's excellent polarization purity over the wideband spectrum.