SIW Cavity-Backed Dual-Polarized Shorted Annular Patch Antenna with High Gain

An SIW cavity-backed shorted annular patch (SAP) antenna with high gain and dual polarization operation at X band is presented. The upper layer is the shorted annular patch and the lower layer is the microstrip feed network. The microstrip line feeds the shorted annular patch through the sectorial annular slot on the ground. The SIW cavity structure is loaded around upper layer and the gain is increased by about 2 dB. Simulation results show that the antenna has a bandwidth from 11.2 to 11.75 GHz at both polarizations and a high port isolation of better than 28 dB. A high broadside peak gain of 10.6 dBi is achieved within the operation band.