Compact filtering crossover design based on SIW quintuple‐mode resonators

Abstract

AbstractA compact filtering crossover utilizing substrate integrated waveguide (SIW) quintuple‐mode resonator (QMR) technology is proposed for the first time. Benefiting from this technology, the proposed crossover firstly breaks the status quo that SIW crossover filtering response is only concentrated in single passband, thereby extending the applications of the SIW crossovers. In design, the QMR is derived by embedding metal‐via holes in the conventional SIW resonant cavity, thus to produce quintuple resonant modes featuring with specific electric distributions. Next, by dividing these modes into two groups, a triple‐mode bandpass filter (BPF) channel and a single‐mode dual‐band BPF channel are both realized. To implement two flat passband channels, there are two SIW cavities cascaded. And also, the isolation between two channels is implemented by employing the orthogonal characteristic. In this way, a crossover is implemented. The proposed design method can be a good candidate for developing SIW multi‐band filtering crossovers. For verification, an example circuit has been designed, fabricated, and measured.