色散媒质覆盖导电体的瞬时散射

本文提出了修正的时域有限差分法（ＦＤＴＤ）来分析计算色散媒质中瞬变场问题，并采用普郎尼近似法使时域卷积可转化为违推计算，是充分利用现代计算机技术解决时域和宽带电磁场问题的一种有效手段。同时运用此方法对色散媒质中及色散媒质覆盖的导体目标瞬时域散射场进行了计算和分析，直观可靠地反映了其特性，并与传统的（非色散）ＦＤＴＤ方法计算的结果进行了比较，差别是显而易见的，为此必须重视色散媒质对瞬变场分析的影响。

Transient Scattering by Dispersive Coated Conducting Objects

The modified finite-difference in time domain(FDTD) method to computation of transient propagation and scattering fields in frequency dependent media is presented in this paper.Using prony's approximation thetime-domain convolution can be calculated recursively.It is an effective way to solve time-domain and wide-bandelectromagnetic problems for dispetsive materials using modem computer technique.The transient scattering by conducting targets in dispersive media and discursive coated targets are computed by this method.Results obtained thisway are visualable and reliable,and are compared with results Obtained by traditional(frequency independent) YeaFDTD method.The differences are clear.We have to pay more attention to the effect of dispersive materials on analyzing transient electromagnetic fields.