Wideband Circularly Polarized Slot-patch Antenna Array Using Series Sequential-phase Feed Network

A wideband high-gain circularly polarized (CP) slot-patch antenna array is proposed in this article. The antenna element has square and circular slots etched in the ground plane, and an incomplete circular patch on the other side. The antenna array is designed by rotating four antenna elements in sequence. And for high gain and wide axial ratio (AR) bandwidth, it is fed by series sequential-phase feed network. The impedance bandwidth (IBW) of the antenna array can reach 74.6% (2.21 GHz to 4.82 GHz) and axial ratio bandwidth (ARBW) can reach 70.6% (2.53 GHz to 5 GHz). The peak gain values are from 2.96 to 9.08 dBi within the ARBW.