The analysis of a balanced-type circular disk resonator excited by coaxial cable lines to measure the complex permittivity

A new structure of a balanced-type circular disk resonator is proposed to determine the relative permittivity /spl epsi//sub r/ and the loss tangent tan/spl delta/ of dielectric plate samples from the measured values of f/sub 0/ and the unloaded Q of the TM/sub 010/ mode. A rigorous analysis based on the Ritz-Galerkin method is preformed to obtain the resonant frequency f/sub 0/ and the Q factors of the TM/sub 0m0/ mode. The numerical results are presented to illustrate the effects of the coupling holes, through which the resonator is excited and detected, on f/sub 0/ and the Q values. The analysis method is used to calculate the values of the /spl epsi//sub r/ and tan/spl delta/ of PTFE plate samples from the measured values.