Abstract: | This article presented a substrate integrated waveguide (SIW) cavity‐backed self‐diplexing antenna array with frequency beam scanning characteristic. The proposed array consists of 16 SIW cavity‐backed slot antennas. The SIW cavity‐backed slot antenna can be fed by two separate ports to resonate at two different frequencies and achieve high isolation better than 20 dB between two input ports. The proposed element is a typical self‐diplexing antenna. These cavity‐backed slot antennas are shunt‐fed by a compact 1 to 16 SIW power divider and series‐fed by a set of microstrip lines, respectively. As a result, this array achieves an unidirectional radiation pattern at 10.2 GHz with high gain of 15.10 dBi, and a frequency beam scanning characteristic from 7.0 to 9.0 GHz ranging from ?50° to 46°. |