A method is presented for the parameter extraction of microwave coupled resonator filters. The method is based on the estimation of a rational model of the filters. From these rational functions, a circuit network having the previously know topology is optimized. Two simple and efficient error functions are used to reduce the computational effort of the optimization while improving the speed and robustness of diagnosis process for lossless and lossy filters, respectively. Two numerical examples are presented to demonstrate the efficiency of the proposed technique. One deals with numerical simulation data from a full-wave electromagnetic simulation and the other one uses the measured data.
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