Broadband High Gain Circularly Polarized Filtering Antenna

This letter proposes a broadband high gain circularly polarized (CP) filtenna. The proposed circularly polarized filtering antenna consists of two radiating patches, a slot coupled feeding structure and a metallic reflector. The CP operation is achieved by the double-Y-shape slot and chamfered patch. This metallic reflector can be used for enhancing the directivity of antenna and antenna gain improvement. In order to realize the filtering radiation performance, a parasitic patch with two diagonal slots is introduced. As a result, two radiation zeros at passband edges are generated, ensuring high frequency selectivity. Simulation results reveal that the antenna’s impedance bandwidth is 59.4% (3.14-5.99GHz) and axial ratio bandwidth of the antenna is 47.3% (3.74-6.01GHz), respectively. The average gain of the broadband high gain circularly polarized filtering antenna is 8.5dBic.