Extension of Levy´s Large-Aperture Design Formulas to the Design of Circular Irises in Coupled-Resonator Waveguide Filters (Short Papers)

This paper extends some results for waveguide irises to obtain accurate design formulas for the design of circular waveguide irises in coupled-resonator rectangular waveguide filters. Experimental results confirm the improved accuracy of the new design formulas. The new approach has been successfully applied to the design of a 12-GHz waveguide filter in WR90 waveguide for satellite transponder studies. Improved accuracy in the iris design enabled the filter to meet stringent group delay specifications.