A broadband dual-polarized microstrip antenna with cavity-backed proximity-coupling feeding

A broadband cavity-backed proximity-coupled dual-polarized microstrip antenna is presented. The cavity backed ground plane is used with optimized parameters to enhance the feeding coupling and thus to broaden the bandwidth of this antenna. A prototype antenna is designed and fabricated. Simulation and measurement results show that the proposed design achieves S11 ≤ -10 dB bandwidth of more than 30% (8.2-11.4 GHz) and the port isolation is larger than 20 dB over that band. This antenna is easy to fabricate, and can be directly mounted on the metal body surface in application.