Computation of the resonant frequency of a dielectric resonator by a differential method

A differential method to compute, with high accuracy, the resonant frequency of a dielectric body with an axis of revolution and placed between two conducting plates is described. The propagation equations, projected on a Fourier basis, are integrated by the Adams-Moulton predictor-corrector algorithm and matched to the modified Bessel expansion of the field. Numerical results obtained for the cylinder shape are compared with those obtained by a modal theory, exhibiting an accuracy better than 10^–4. Results for a dielectric sphere are given as another application.