Dual Band Dual Mode Substrate Integrated Waveguide Filter With Mixed Coupling

This letter presents a dual-band substrate integrated waveguide (SIW) filter based on the dual modes of TE101 and TE102 in multilayer structures. Its middle metal layers feature mixed-coupling structures, where the slots implement independent magnetic coupling for the TE101 and TE102 bands, and the holes implement additional electric coupling for the TE101 band. It can independently control the dual bands and their transmission zeros (TZs), allowing for flexible design and controllable selectivity. A prototype is provided with independent dual bands and controllable TZs located between them. The proposed technique should be effective for developing high-performance dual-band SIW filters in microwave and wireless circuits and systems.