摘要
本文全面介绍了非正交FD-TD方法的基本原理,推导出了其稳定条件和数值色散方程,并对其数值色散特性进行了详细分析研究。用非正交FD-TD方法在正弦波激励下对无限长三角形导体柱TM散射电流进行了计算,与矩量法(MM)结果基本吻合,证明了其有效性。在此基础上对涂敷多边形导体柱的TM散射问题进行了计算,得出远区单站RCS结果,同时为了比较给出了分别用非正交FD-TD法和等效源法计算涂敷方形导体柱的散射场分布的结果。
The foundational principle of the nonorthogonal PD-TD algorithm is introduced, and its stability condition and dispersion equation are derived. The numerical dispersion characteristics of this method are analyzed in detail. In order to show its validity the scattering surface currents of perfectly conducting cylinder are calculated by using this method when the incident wave is sinusoidal plane wave in TM case. The numerical results agree with that by moment method very well. Then the TM scattering problem of polygon cylinder coated with absorbing material is studied and the monostatic RCS of the target is obtained. For comparison with results of equivalent source method the electric scattering distribution pattern of square cylinder coated with absorbing material is also obtained by using nonorthogonal FD-TD.
关键词
电磁散射
时域有限差分
导体柱
Electromagnetic scattering, Finite difference time domain, Conducting cylinder
