摘要
TF/SF(TotalField/ScatteredField)法是FDTD(Finite-DifferenceTime-Domain)数值算法中引入平面波源的有效方法之一。本文对TF/SF法中的一维辅助波源法进行改进,首先推导出三维FDTD网格内的电磁波传播群速和相速的近似解析解,为预测离散网格内电磁波传播提供理论基础;然后以此为依据,提出对一维辅助波源的时域群速补偿法。经过实际三维FDTD问题的数值模拟,证实了本文方法在保持一维辅助波源法高效简洁的同时,进一步减少了泄露误差,给FDTD计算散射问题提供了有力工具。
TF/SF is an effective method in introducing plane wave source in FDTD. This article makes some improvement in TF/SF. Analytic forms of group and phase velocity of Electro-Magnetic( EM )waves in 3D FDTD grids are derived firstly as the theoretical foundation. Based on the fact that wideband EM wave propagates with its group velocity, a time domain group velocity based adjustment method is put forward. Numerical simulations are conducted to confirm the advantages of this new method to others, which not only improves accuracy but maintains the simplicity as well. And the practical power of this new method in 3D FDTD codes is validated.
出处
《信息与电子工程》
2006年第3期175-180,共6页
information and electronic engineering
关键词
计算电磁场
时域有限差分
全场/散射场法
速度补偿
computational EM waves
Finite-Difference Time-Domain(FDTD)
TF/SF
velocity adjustment