Wideband Substrate-Integrated Cavity-Backed Elliptical Slot for Microwave Synthetic Aperture Imaging

Abstract

Resonant elliptical slot antennas with waveguide feeds were successfully used to implement the microwave imaging systems in the past. For wideband imaging, these slots required tuning circuit components to be incorporated in the array. The bulkiness of the previous feeds and the additional tuning circuits render realizing wideband large imaging arrays practically prohibitive. In this paper, the feeding and bandwidth constrains of the previous elliptical slot designs are addressed. Specifically, a unidirectional wideband substrate-integrated cavity-backed elliptical slot antenna is introduced for imaging applications in the $K$ -band frequency range (18–26.5 GHz). The proposed slot design and measurement results are presented herein. Its efficacy for imaging applications is demonstrated via synthetic aperture imaging.