A Broadband Dual Circularly Polarized Square Slot Antenna

Abstract

A novel coplanar waveguide-fed broadband dual circularly polarized square slot antenna is presented. The antenna consists of a square slot, two asymmetric T-shaped feed lines in orthogonal direction protrude from signal lines, and an inverted-L grounded strip with three straight strips at the corner of the slot adjacent to both the feed lines. The circular polarization is obtained due to orthogonal feed lines. Axial ratio (AR) bandwidth is significantly enhanced because of inverted-L grounded strip with attached three straight strips. The 3-dB AR bandwidth of the antenna is about 60% in which return loss, and isolation are better than 10 and 15 dB, respectively.