Development of a Low Profile Wideband SIW Cavity-backed I-shaped Slot Antenna

Abstract

In this paper, a bandwidth improvement technique in substrate integrated waveguide (SIW) slotted antennas is presented. Here, wideband is achieved by using a single cavity mode (TE 210 ) instead of multiple cavity modes, which is the most distinct approach as compared to other SIW based antennas. When the rectangle slot is loaded at bottom surface of the cavity, the TE 210 cavity mode of the antenna is perturbed. As a result, two independent modes namely odd TE 210 and even TE 210 are successfully generated and merged in close proximity. Consequently, an impedance bandwidth of 12.8% is obtained. When a vertical slit is added at each end of the rectangle slot to make as an I-shaped slot, the impedance bandwidth is increased from 12.8% to 13.94%. The fabricated antenna shows the measured impedance bandwidth of 14.4% and exhibits a gain of 5 dBi to 7 dBi throughout the operating band. The proposed design still retains many features such as light weight, easy fabrication, and easy integration.