A compact multilayer dual-mode substrate integrated circular cavity (SICC) filter

A novel high-performance millimeter-wave multilayer dual-mode filter is developed based on the substrate integrated waveguide circular cavity (SICC). The filter with two or three SIW circular cavities has been designed for Ka-band application. The multilayer dual mode filter has been firstly realized only by adjusting the coupling aperture located in input/output port and between layers. The position and size of coupling aperture can determine the coupling amount between two degenerate modes. This novel filter is very compact, and the simulated results prove it has the advantages of return loss, very low insertion loss, high selectivity, what´s more it can be found that the upper side response of the filter are very steep.