A Millimeter-Wave Slot Antenna Array Radiating Sum and Difference Beams with Suppressed Sidelobe

This paper presents a monopulse antenna array with sum/difference beams and suppressed sidelobe. A compact antenna structure is obtained by combing the substrate integrated waveguide (SIW) slot array and metallic waveguide feed network. The peak gain of the proposed antenna is up to 34dBi at 93GHz, with -23dBi sidelobe level. The sum-difference contradictions are less than 4dB, amplitude balance between two difference peaks is less than 0.17 dB, and the nulls of difference beam are below -40dB. The proposed antenna has advantages of low profile, circular surface, and high performance, which is suitable for monopulse applications.