A broadband proximity-coupled dual-polarized microstrip antenna with L-shape backed cavity for X-band applications

A broadband proximity-coupled dual-polarized microstrip antenna with a L-shape backed cavity is presented. The L-shape cavity backed ground plane is used to enhance the feeding coupling and thus to broaden the bandwidth of this antenna. The parameter study is done in detail to show the guideline of designing this antenna. A prototype antenna with optimized parameters 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 has a relatively simple structure, and can be directly mounted on the metal body surface in application.