A Broadband Patch Antenna With Tripolarization Using Quasi-Cross-Slot and Capacitive Coupling Feed

This letter presents a novel design of patch antenna with quasi-cross-slot and capacitive coupling feeding to achieve tripolarization with high isolation over a wide bandwidth. Two degenerate TM11 modes and one TM01 mode of the circular patch antenna are generated to realize three orthogonal polarizations. By using the proposed quasi-cross-slots, good measured isolations (better than 20 dB) were obtained. The measured impedance bandwidths of the proposed antenna ports are 2.13-2.58, 2.13-2.43, and 2.13-2.58 GHz, respectively. Details of the proposed design and measured results are presented and discussed.