Design of waveguide filters without tuning elements for production-efficient fabrication by milling

A filter design process is presented which allows the components to be readily manufactured by milling machines using relatively large cutters. This process makes the production more cost-effective and efficient. Several examples in the WR75 waveguide band demonstrate the feasibility of the design procedure. Moreover, we address the differences in the manufacturing plane and the possibility of using different end-mill radii in different parts of a component. The design data are verified by comparing results of the mode-matching technique and those of the finite-element method (HFSS).