Design and tolerance analysis of thick iris waveguide bandpass filters

The design and tolerance analysis of a thick iris waveguide filter are described. In order to design the filter exactly, numerical techniques are used to model the iris and coaxial-waveguide junction. A novel equivalent circuit is derived and is used to compute the dimensions of the filter. Tolerance analysis determines the requirement of the manufacturing tolerances. Experimental results show that the performances of the filters, with no tuning, agree well with the design goal. This technique can be extended to other filter types to study the feasibility of the exact design and is the foundation for applications for dielectric-filled waveguide filters