Ka-band waveguide filter synthesis using mode-matching method

In this paper, a mode matching method is discussed in application to waveguide filter synthesis task. It is customized for analysis of particular waveguide filter with thick symmetric irises. Equivalent circuit model of thick iris discontinuities is also proposed. Parameters of the equivalent circuit are evaluated using mode-matching method. Using this model, an example filter for Ка-band has been designed. The performance of the filter has then been validated by the discussed method, by finite-elements method and by direct measurements of manufactured filter. A novel fabrication technique which eliminates the need in trimming screws is also elaborated.