A hybrid synthesis technique for N-tuplets microwave filters cascaded by resonator

A novel hybrid technique for synthesis of N-tuplets microwave coupled-resonator filter is proposed in this paper. This new approach only requires little numerical optimization. The original coupling matrix is first transformed to a midway structure, which consists of two sub matrices cascaded by a resonator. Then each sub matrices can be individually transformed to an N-tuplets structure by available similarity transformations. Hence, the proposed technique combines the advantages of both exact synthesis and numerical synthesis. Moreover, more flexible filter topologies can be obtained by this new procedure.