A Novel Double U-slot Microstrip Patch Antenna Design for Low-Profile and Broad Bandwidth Applications

A low-profile double U-slot microstrip patch antenna with a wide operating bandwidth has been developed in this paper. This design produces the dual radiative resonant modes adjacent to each even at the thickness of the antenna of 0.02λ0. And an extremely stable radiation gain varied from 6.2 to 6.8 dBi is achieved within the whole operating band. In addition, detailed parametric studies in this paper provide antenna engineers with simple approximate rules that result in an excellent first-pass design with prescribed characteristics requiring only minimal tuning. Finally, the proposed antenna with the thickness of 0.04λ0 is fabricated and measured. Simulated and measured results are found in good agreement with each other. They have evidently illustrated that the bandwidth is increased by 50% compare to the traditional U-slot antenna. With the help of these simple design procedures and examples in this article, antenna designers could easily develop a low-profile broadband antenna.