Field Design of TE011-Mode Wavegude Passband Filters

A modified mode-matching technique for the analysis of waveguide bandpass filters employing circular T E011 resonators, coupled by rectangular apertures, is presented. The technique rigorously takes into account both the thickness of the coupling irises and the angle between the irises of the same resonator, overcoming the limitations of available approximate models. By optimization procedures it is so possible to design filters having the desired frequency response without resorting to empirical adjustments. Spurious responses can be controlled too, as verified experimentally.