Analysis of dielectric resonators using the FDTD method combined with the Pade interpolation technique

The finite-difference time-domain (FDTD) method incorporating Berenger's PML absorbing boundary condition is developed to model three-dimensional dielectric resonators. The fast Fourier transform (FFT) coupled with the Pade interpolation technique is employed to obtain frequency domain results with satisfactory resolution and accuracy, and to reduce the computation time significantly compared with that needed when the conventional FFT algorithm is used. Computed resonant frequencies of two types of cylindrical dielectric resonators are compared with theoretical and measured results. A good agreement is observed.