Sequential Parameter Extraction of Direct-Coupled Resonator Filter

A new parameter extraction method for Direct-coupled resonator filters is presented. Matrix Rotation technique is used for extracting all the filter parameters (resonant frequencies of all resonators and coupling between adjacent resonators) from its reflection phase response. This method is capable of extracting accurate coupling and resonant frequencies of Direct-Coupled resonator filters. This simple and straight forward method will help in optimizing and tuning of Direct-Coupled filters and can also be useful for characterizing cross-coupled filters.