Multilayer substrate integrated hexagonal cavity (SIHC) filter with mixed coupling (MC)

Abstract

A novel multilayer substrate integrated hexagonal cavity filter with mixed coupling (MC) is proposed. Based on the substrate integrated waveguide techniques, the filter configuration is composed of hexagonal resonators which combine flexibility of rectangular cavities and performance of circular cavities. Meanwhile, by introducing MC into two adjacent resonators in the middle layer, the proposed filter has not only good selectivity due to the controllable transmission zeros, but also a compact size by profit from low-temperature co-fired ceramic technology. A fourth-order bandpass filter with three transmission zeros has been designed and fabricated. The measured results validate the feasibility of the proposed design, with its high selectivity demonstrated.

Acknowledgments

This work was supported by the National Natural Science Foundation of China (Grant No. 61101030, 51172034), and Fundamental Research Funds for the Central Universities of China (Grant No. ZYGX2011J132).