A Broadband SIW Cavity-backed Circular Arc-shaped Slot Antenna for Millimeter-wave Applications

Abstract

A broadband circular arc-shaped slot antenna is proposed in this paper which operates from 25.1 GHz to 31.5 GHz. The antenna is based on a substrate-integrated waveguide (SIW) and fed through a grounded coplanar waveguide (GCPW). A circular arcshaped slot is presented instead of a conventional narrow rectangular slot to extend bandwidth performance. The slot antenna generates six closely resonant frequencies by exciting high-order modes, which help get a broadband response. Antenna's prototype is fabricated using the standard Printed Circuit Board (PCB) process. The results of its measurement show that the antenna achieves an impedance bandwidth of 22.6% at 28 GHz and a peak gain of 11.5 dBi. The efficiency in the operating bandwidth is more than 85%. The antenna shows the merits of low-profile, high-gain, and broadband characteristics, which are very suitable for mm-wave wireless communication systems.