A Ka-Band Wideband SIW Cavity-Backed Slot Antenna Array

Abstract

A wide band substrate integrated waveguide (SIW) cavity-backed antenna operating in Ka band is presented in this paper. The proposed SIW cavity is octagonal with two trapezoidal slots on it. Additional substrate is added upon the cavity as an impedance transformer. Then a $2\times 2$ antenna array is designed to further increase the antenna gain. Simulated results demonstrate that the $\vert \mathbf{S}_{11}\vert < -10\ \mathbf{dB}$ impedance bandwidth of the proposed antenna reaches 30.2% (23.0-31.2 GHz), and the antenna array achieves 20.2% (24.5-30.0 GHz) impedance bandwidth and stable gain throughout the operating bandwidth with a peak of 13.8 dBi.