Siw based dual fed cavity-backed self-diplexing slot antenna

In this paper a simple and planar kind substrate integrated waveguide (SIW) based cavity-backed self-diplexing antenna geometry for the X-band is proposed. This antenna is a suitable design for amateur radio and satellite communication systems. Here the SIW cavity is formed a half mode and a quarter mode cavity. These cavities are excited by two separate and orthogonal 50 Ω micro-strip feed lines. An angular radiating slot is etched on the upper metallic quarter mode cavity and a transversal slot is etched on the top of the half mode cavity, which produces the two distinct resonant frequencies of 10.0 and 10.5 GHz, respectively. By properly tuning the antenna dimensions, the better isolation of ≥ 30 dB between the two input ports is achieved, which approaches to the self-diplexing property of the antenna. The fabricated antenna shows a close agreement with simulated results. The proposed antenna gives a better amount of cross-polarization (<- 20.5 dB), the reasonable value of FTBR (> 21 dB), and a unidirectional radiation pattern with measured gain of 4.8 dBi and 5.1 dBi at both working frequencies. ©2020 by Begell House, Inc.