Two-Layered Cross-Coupled Post-Loaded SIW Filter With Microstrip Ports

In this brief, we propose a new structure for reducing the number of substrates of a post-loaded substrate-integrated waveguide (SIW) resonator filters with microstrip ports. For using fewer substrates, the proposed structure has microstrip ports and each capacitive gap (the dielectric gap between one side of each post and the ground) on one side of the filter structure, which has not been reported to date. Hence, it does not necessitate another substrate designated for the implementation of the dielectric-filled gaps for the capacitive posts of post-loaded resonators. In addition, a new cross coupling structure for SIW resonators is also presented in this brief. Negative couplings can be easily implemented by using the proposed slot structure.