Design of crossed-SIW directional couplers with different angles

The design of crossed-SIW 3-dB directional couplers with different angles has been presented in this paper. A prototype coupler was fabricated by PCB process. Measured results prove the design's validity and show fine agreement with the simulation ones. Further work could be done to enlarge the operating bandwidth by design a better H-plane transition structure from central cross region to extended SIW sections.