A wideband aperture‐coupled microstrip array using backed substrate integrated cavity with T‐shaped geometry

A novel 2 × 2 wideband cavity‐backed aperture‐coupled microstrip array is presented in this article.The cavity in the antenna element is designed based on the new substrate integrated cavity technique and has a T‐shaped geometry. It affords a solution to enhance the bandwidth, reduce the back radiation of the aperture, and suppress the parallel plate mode simultaneously. Furthermore, an integrated multilayer architecture of the feeding network is used in the array. The experimental results of the array show the bandwidth exceeds 40% (VSWR < 2), and the cross‐polarizations of E and H planes are all lower than −20 dB.