Pillbox antenna with monopulse technique and wide scanning capabilities for tracking applications

Two identical and opposite pillbox structures are used to design a multibeam antenna with monopole phase comparison technique for tracking and direction finding applications. The scanning capabilities of pillbox systems and enhanced resolution of two-quadrant monopulse techniques are combined is the same antenna system. This approach avoids mechanical steering of the antenna system for tracking. The antenna is a dual layer structure; the feeding system (based on horn and hybrid couplers) is integrated in the lower layer, whereas two slotted-waveguide sub-arrays that constitute die two-quadrant monopulse he in the upper layer. The beam is steered in E-plane over an angular range of ±40° by switching between seven integrated horn pairs. Sum and difference patterns are generated in H-plane. The antenna structure is implemented is Substrate Integrated Waveguide (SIW) technology in the 24-GHz band. The measured and the simulated results are in good agreement.