Substrate Integrated Waveguide Multi-Channel Filtering Crossover With Extended Channel Number and Controllable Frequencies

In this brief, substrate integrated waveguide (SIW) multi-channel filtering crossovers are proposed for two sets of intersecting signals operating at the same or different frequencies. The number of filtering channels in two directions can be independently extended. Square SIW cavities with TE102 and TE201 modes are used as building blocks. By properly arranging feeding ports and coupling regions, isolation between different channels is achieved and bandpass responses are integrated. The design procedure can be simplified as that of single-channel bandpass filter. For demonstration, a six- and a five-channel filtering crossovers with the same operating frequency in two directions are designed and fabricated. By etching a slot on the square SIW cavity, the TE102 and TE201 modes are split and thus the frequencies can be controlled. A four-channel filtering crossover with different operating frequencies in two directions is implemented for further verification. Compared to other multi-channel crossovers, the proposed designs feature good inter-channel isolation and intra-channel filtering responses with flexibly extended channel number and controllable frequencies.