Mode matching analysis and design of waveguide E-plane filters and diplexers

Abstract

Implementations of wireless techniques call for low return and insertion losses and high slope selectivity of mm wave devices. Not many structures potentially satisfy all of the above criteria. In this work, diplexers with E-plane filters combined with an H-plane Y-junction splitter are investigated. The Y-junction configuration of the splitter is chosen based on its favorable S-parameter behavior. Filter analysis is facilitated using the mode matching technique (MMT). Based on this analysis, a band pass filter for the K band was built and tested. In order to integrate the filters with the Y-junction, the filters are positioned appropriately along the junction arms. The integrated filter-junction structure was then analyzed by an MMT code for the entire structure. An integrated diplexer model was built and tested, confirming the predicted performance based on the MMT.