Circularly polarized high gain multiband antenna for non-linear junction detector system

This paper proposes a design of multiband circular polarization patch array antennas for non-linear junction detector system application. A patch antenna with the inclined three slots, two rectangular grooves on circular disc patch, the asymmetric gap of the CPW feeding structure and the truncated corner of g round plane w as considered for circular polarization and broad bandwidth. In order to improve gain and to keep small size in array antennas, the optimized rectangular slot array located on common ground plane was designed. The calculated and the measured return loss and axial ratio of array antennas were showed good agreement. The higher gain of about 1 dBi was realized by using the common ground structure with the novel slot array to suppress mutual coupling.