A Multilayer Substrate Integrated Circular Cavity (SICC) Dual-mode Filter Using a Novel Topology of Coupling

A compact multilayer dual-mode filter is developed using a new topology of coupling in this study. The filter is constructed with three Substrate Integrated waveguide Circular Cavities (SICC) and each cavity supports two degenerate modes, which is generated by the double arc-shaped slots located between layers. With multilayer topology, the structures can exhibit vertical coupling between vertically stacked dual-mode cavities. This coupling is achieved by double arc-shaped slots with same center, which are etched in the metal layers of cavities. The novel topology is used to improve the stop-band rejection, and suppress some undesirable response spur in transition band. Good agreement is obtained between the simulated and measured results of the proposed structure.