Measurement of the Dielectric Resonator Complex Permittivity Using Cavity Resonator-Evanescent Waveguide Technique

This paper is concerned to a TE 01n mode resonator coupled through a hole located in the center of the end wall to a waveguide supporting the evanescent TE 01mode.When the evanescent guide contains a dielectric resonator,propagation of TE 01 wave will be permitted in the dielectric filled part.The air filled part in front of the dielectric resonator is used to adjust the coupling level,the air filled part behind the dielectric resonator is used to form a matched reactance termination;otherwise, a metal block is inserted to form a short circuit termination. It is shown that while using these arrangements quite a large change in the resonant length and Q-factor of the cavity resonator will be obtained,when a dielectric resonator is inserted into the evanescent guide.Therefore the accurate values of the complex permittivity for dielectric resonator will be extracted.Fundamental princirples and the experimental restriction are discussed.Measurements for the ceramic resonator are reported also.