Integration Designs of Waveguide Slot Array Antenna with Filter

This paper presents several filtering designs for waveguide slot array antennas. By incorporating various filter structures, such as metal nails, metal mushrooms, metal sheets, etc., inside or at the bottom of the waveguide slot array antenna, the antenna can exhibit stopband characteristics outside its operating frequency range. These characteristics include single stopband and dual stopband, which effectively enhance the antenna's ability to suppress out-of-band radiation without affecting its size and radiation performance.