Accuracy Analyses of FDTD Resonance Frequency Calculations for a Partially Dielectric‐Filled Cavity
Osman S. Bişkin, Talha Saydam, Serkan Aksoy ABSTRACT
In this study, accuracy analyses of resonance frequency calculations for a three‐dimensional partially dielectric‐filled cavity are investigated by using finite difference time domain (FDTD) method. The calculations are performed for low‐ and high‐contrast lossless dielectric materials. In order to excite multicavity modes, the cavity is driven by a Gaussian pulse source. The main error sources for the numerical resonance frequency calculations of the partially dielectric‐filled cavity are (i) applied technique for treatment of a dielectric interface between free space and material medium and (ii) numerical dispersion of the FDTD method. The effects of these errors are analyzed both in detail. A no averaging (without any averaging), a proper averaging technique for the low‐/high‐contrast case, and the dielectric functioning technique with three different distances of are applied for the treatment of dielectric interface. Additionally, four spatial resolutions of , , , and are used for the numerical dispersion analyses. The calculated results are compared with a semianalytical solution for the accuracy evaluations. Specially, in order to explain ordering of numerical errors for each case, a technique based on electromotor force calculation is proposed with good success. The computational advantages of the applied techniques are also shown over no averaging case.