On the Design of Microwave Filters with Coupled Resonators

摘要

In this paper a synthesis method is presented, which is generally applicable to symmetric or asymmetric charac- teristics of microwave bandpass filters with coupled resonators. The realization procedure is based on low-pass prototype filters with reactive circuit elements. Commencing with the scattering coefficients S_11(p) and S_21(p) the transfer matrix polynomials are constructed. It is shown that with the circuit elements capacitor, frequency- invariant susceptance and imaginary admittance inverter low-pass prototype filters are designed that may be realized in microwave bandpass filters with coupled resonators.