Direct Matrix Synthesis for In-Line Filters with Transmission Zeros Generated by Frequency-Variant Couplings

摘要

A general approach for in-line filters that contain a set of frequency-variant couplings is presented in this work. By utilizing an absolute matrix transformation process, the synthesis is distinctive from all other similar literatures because no optimization is required. In result, it is shown that multiple transmission zeros can be individually generated by the frequency-variant couplings. Moreover, some unique topologies where in-line frequency-variant couplings are connected with traditional extracted-pole sections and cross-coupled structures are introduced. For validation of the proposed approach, a group of examples with practical results are demonstrated.