The Research Of Computer-aided Tuning Method Of Cross-coupled Resonator Filters

This thesis focus on the computer-aided diagnosis and tuning method for cross-coupled resonator cavity filters. Firstly, based on general equivalent circuit model for coupled resonator filters, the synthesis is discussed using the orthogonal transformation of the coupling matrix. Also S-parameters are expressed in the coupling coefficients. By the HFSS9.0, the electric and magnetic filed distributions of main mode in the resonator cavity are plotted. The coupling characteristics of several cross-coupling structures have been analyzed. Then, the tuning characteristics of tunable elements in filter are presented. Some important and practical tuning methods and skills are described in detail. Finally, computer diagnosis method of de-tuned filters and its realization are studied fully and a computer aided tuning method is provided. The corresponding computer programs written using MATLAB are presented. The provided examples validate this method.