SIW pillbox antenna integrating monopulse phase comparison technique

A multi-beam pillbox antenna system incorporating monopulse phase comparison technique is proposed in the 24-GHz band. The antenna architecture combines the scanning capabilities of pillbox couplers and enhanced resolution of the two-quadrant monopulse technique. This approach avoids mechanical orientation of the antenna system for tracking applications. The beam is scanned in E-plane over a field of view of ±40°, and sum/difference patterns are generated in H-plane. The measured null depth is better than -16 dB for all difference beam patterns around the design frequency, f=24.15 GHz. The measured reflection bandwidth for VSWR<;2 equals 4.5%, and the isolation between the sum and difference input ports is better than 17 dB over the [23.5-24.6] GHz band.