The Research Of Substrate Integrated Waveguide Filter

The miniaturization of substrate integrated waveguide (SIW) filters and themulti-mode SIW cavity filters are studied in this paper.In terms of miniaturization, there is a combination of the compact nature of thecomplementary split ring resonator (CSRR). This structure allows the implementationof a forward-wave passband propagating below the characteristic cutoff frequency ofthe waveguide. THe application of SIW and CSRR combination technique to the designreaches the goal of miniaturization. Lumped parameter model is constructed to simulatethe corresponding results. To verify the presented concept, a K-band band-pass filter isdesigned and fabricated, the measured results are in good agreement with thesimulation.In terms of cavity resonators, the procedure to design a filter based on thefundamental mode of SIW is given. It mainly relys on the coupling matrix.The casewhen coupling is insufficient is discussed and solved by adding slot line. In addition, adual-mode filter based on the TM110degenerate mode of the waveguide is design andfabricated. Moreover, the structure is successfully applied to W-band. It expeditesproceedings of the millimeter wave planar integrated device. Finally, a novelthree-mode resonator is investigated. The proposed structure is realized by thecombination of TM110degenerate mode and fundamental mode whose frequency isincreased by perturbations in the center position. Some filters are designed andfabricated to varify the presented concept. The experimental results show thatthree-mode filters have better out-band rejection than similar dual-mode filters.