Abstract
In the past, several extrapolation techniques have been used in conjunction with the finite-difference-time-domain algorithm to reduce the computational cost involved in obtaining an accurate representation of the frequency response of the electromagnetic system under consideration. In this article we study the performances of different autoregressive techniques in accurately estimating the spectra of finite-difference-time-domain waveforms without resorting to extrapolation. The advantages and disadvantages of these techniques are demonstrated through two examples: a package plane structure and a cavity. (C) 1994 John Wiley & Sons, Inc.