Synthesis of resonators filters with arbitrary mixed topology using hybrid method

Abstract

In this paper a hybrid optimization synthesis method is presented for arbitrary mixed topology microwave filter (i.e., part of the structure with an extracted-pole and part with cross-coupled configurations). Compared with the conventional synthesis method for mixed topology filter, the method presented in this paper has following advantages: 1. There is no rotations for coupling matrix. 2. The method is suitable for terminal extracted-pole sections and inside extracted-pole sections. 3. It is no need to care the extra phases for the characteristic polynomials. This method consists of a genetic algorithm (GA) for a global optimizer and Solvopt for a local optimizer, respectively. Four examples are given for illustrating the proposed techniques for the synthesis of mixed-topology prototype filters. Excellent agreement between the response computed from characteristic polynomials and the response computed from couplings is obtained from the proposed method.