Analytical synthesis of coupling matrix for a dual mode dual band filter

Abstract

ABSTRACTIn this article, a simple approach for synthesis of coupling matrix of dual mode dual band filters is presented. Odd and even modes of dual mode cavities are used as basis of this coupling matrix. Each mode of cavities is coupled to the same mode of the adjacent cavity independent from the other mode and hence, two separate paths, odd path and even path, are provided from source to load. Therefore, the sensitivity of filter with respect to the fabrication tolerance is reduced. For validation of this approach, the coupling matrix of two‐cavity dual mode dual band filter is calculated and also, a dual mode dual band SIW filter by using corner cut square SIW cavities is designed and realized. Filter prototype is fabricated on a single layer substrate using PCB technology and the measured results are in a good agreement with the simulated results. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:80–83, 2017