A Unified Ridge Structure for Evanescent Mode Wideband Harmonic Filters: Analysis and Applications

This paper present an accurate analysis of various applications of a double antipodal ridge waveguide structure which is loaded with different dielectric materials Design parameters, i.e. the cutofff frequencies of the TE10 and TE20 modes, equivalent dielectric constant, characteristic and gap impedances have been calculated. This versatile type of ridge structure can be considered a unified structure for evanescent-mode ridge waveguide lowpass and bandpass harmonic filters. A great deal of flexibility in the choice of size, power handling capability, out-of-band isolation, and bandwidth can be achieved. The accuracy of the analysis has been verified by the development of a widehand bandpass filter using evanescent mode serrated double antipodal ridge structure. Test results are provided.