Efficient and accurate finite-difference time-domain analysis of resonant structures using the Blackman-Harris window function

Abstract

In this paper, we present a technique, based on the principle of the frequency-domain convolution of a time-domain signature and a truncation window function, to process the electromagnetic field solution in a resonant structure derived by using the finite-difference time-domain (FDTD) algorithm. We show that the use of this technique enables us to substantially reduce the total number of iterations provided that certain criteria are imposed on the time and frequency resolutions, as well as on the Nyquist sampling rate. The conventional approach to terminating the time iteration is to employ a rectangular windowing (RGW), which induces the unwanted Gibbs phenomenon in the frequency domain. To avoid this, we apply the Blackman–Harris window (BHW) function which modulates as well as truncates the computed time-domain electromagnetic signals. We demonstrate via a numerical experiment that the BHW modulation and truncation yield excellent results with only a small number of iterations, often only one-tenth of that needed in the RGW method. © 1997 John Wiley & Sons, Inc. Microwave Opt Technol Lett 15: 389–392, 1997.