A method to improve coupling of aperture-coupled microstrip antenna with backed substrate integrated cavity

The coupling of aperture-coupled microstrip antenna with a backed substrate integrated cavity (SIC) is related to the SIC shape. To improve the coupling and try to reduce the size of the aperture, a method is presented in this paper by changing the shape of cavity. Due to the increase of the coupling, the bandwidth of the antenna will be enhanced with a relative smaller aperture, which is benefit for the antenna miniaturization.