SIW Pillbox Antenna for Monopulse Radar Applications

A multibeam pillbox antenna system incorporating monopulse phase comparison technique is proposed in the 24-GHz band. This low-profile antenna architecture combines the scanning capabilities of pillbox configurations and enhanced resolution of two-quadrant monopulse technique; this approach avoids mechanical orientation of the antenna system for tracking applications. The radiating panel consists of two subarrays of 23 slotted waveguides, with 8 slots per waveguide. The beam is scanned in E-plane over a field of view of , and sum/difference patterns are generated in H-plane. Around the design frequency, , the antenna gain varies between 25 and 21.5 dBi for the central and extreme beams, respectively. The measured null depth is better than for all difference beam patterns. The antenna bandwidth for ( ) and isolation better than ( ) is equal to 4.5%.