Numerical Analysis of Eigenvalue Solution of Disk Rescmator

A formulation is proposed to calculate the frequencies of the eigemnodes for a resonator with a thin conductor disk placed in the median plane betwe-en two infinite parallel conductor plates. The numerical tialysis"is c~ried out for the E- and Ek?-rnodes, and these eigenvalues are calculated as the function of the ratio of the disk radius to the distance between me d!sk and one of the @finite conductor 'plates. It is shown that at a ratio gre"ater than a certain vah!e"the exact eigenvalue is smaller than the one predicted by ap- plying the conventional method for two-dimensional bifurcation of rectangular waveguide, but the latter becomes closel to me exact one with 'increasing ratio. The availability of our exact eigenvalues is demonstrated in "determining experimentally the dielectric constant of Teflon plate specimen by applying those vtiues. Then the constancy of the measured dielectric const~t is confirmed irrespective of the modes and the ratios,