A novel cavity-backed wideband microstrip single layer patch antenna

This paper presents a novel class of cavity-backed, wideband microstrip single layer patch antenna. The radiating patch is fed by microstrip line, and they are both etched on the topside of a thin substrate. In order to increase bandwidth, two kinds of especial shape patch are employed. The first is E-shape, simulations and measurements show that this kind of antenna can realize 45% impedance bandwidth for VSWR ≤ 2, but its pattern bandwidth is narrow. To suppress cross-polarization, the second modified E-shape patch is proposed, which cutting three slots on the E-shaped patch. It can achieve 13.5% impedance bandwidth for VSWR ≤ 1.5, with low cross-polarization of less than -11.0dB across the operated band. The design and measured performance of an 8 × 16 subarray with this element are also presented.