A novel design of modified I-shaped low profile broadband cavity-backed SIW slot antenna

Abstract

This article proposes a novel procedure to enhance the bandwidth of substrate-integrated waveguide (SIW) slotted antennas. By introducing a rectangular slot on the cavity's bottom surface, the TE210 cavity mode is perturbed, leading to the successful generation and merging of odd and even TE210 modes. This approach achieves an impedance bandwidth of 13.5%. To further enhance the bandwidth, the rectangular slot is modified into an I-shaped slot by adding vertical slits at each end, increasing the impedance bandwidth to 15.1%. Placing the modified I-shaped slot on the ground plane further enhances the impedance bandwidth to 17.2%. The constructed antenna maintains a gain of 7.83 dBi at 10.2 GHz and 7.85 dBi at 11.4 GHz, with a measured impedance bandwidth of 19.04%. The design retains several advantageous features, including lightweight construction, easy fabrication, and seamless integration.