Compact Integrated Duplex Filtering Antenna with Common Feeding and Radiating SIW Cavities

In this paper, a compact integrated duplex filtering antenna is proposed based on co-shared substrate integrated waveguide (SIW) cavity. Firstly, a dual-mode TE102 and (TE201 modes) rectangular cavity with two input ports is utilized as a common feeding cavity to respectively contribute one transmission poles for each channel. And then, an additional square cavity with a rectangular ring slot is coupled from the lower feeding cavity for both dual-mode excitation and duplexing passband radiation. To verify the proposed concept, a prototype duplex filtering antenna is simulated. The duplex filtering antenna resonates at 7.27 GHz and 8.06 GHz with a low cross-polarization and a high gain of 5.82 dBi and 6.91 dBi, respectively.