A Fast Computer-Aided Method for Filter Design Based on Vector Fitting

Traditional filter design methods heavily rely on electromagnetic (EM) simulations and a trial-and-error process, resulting in low efficiency. These methods fail to provide clear optimization directions under predefined filter topologies and performance specifications, leading to increased computational resource consumption. To address this issue, we propose a fast computer-aided design method based on vector fitting. This method de-embeds and fits the S-parameters of the filter to accurately extract and optimize the coupling matrix, significantly simplifying the design and optimization process. Furthermore, it provides clear optimization targets, reducing design complexity and improving optimization efficiency. To validate the effectiveness of the proposed method, a high-temperature superconducting filter, which presents significant tuning challenges, is used as an example. The results demonstrate that this method significantly enhances the efficiency of filter design and optimization while reducing the design difficulty.