有损耗左手材料电波传播特性的FDTD分析

为研究电磁波在有损耗左手材料中的传播特性,采用时域有限差分（FDTD）法和色散媒质的Drude模型,推导出基于Drude模型的左手材料二维FDTD迭代方程。一维数值仿真结果验证了平面电磁波在穿过有耗左手材料时,其相速度大小与光速相同,方向与传播方向相反,且随着损耗因子的增大,左手材料内的电场强度幅值亦相应减小。此外,还利用多循环m-n-m脉冲作为激励源,对左手材料平板具有的完美透镜现象进行了二维数值仿真验证。结果表明,有耗平板左手材料具有明显的聚焦效果,在特定条件下能实现完美成像。

Analysis of Electromagnetic Wave Propagation Characteristic in Lossy LHM by FDTD Method

The Drude-based two dimensional FDTD iterative equations in LHM were deduced by FDTD method and the dispersive Drude model in order to study propagation characteristic of electromagnetic wave in left-handed materials（LHM） . One-dimensional simulation results show that the phase velocity of a plane electromagnetic wave propagating inside a LHM is equal to the velocity of the light while the direction is converse,and the amplitude of electric field is reduced with the increase of loss factor.Furthermore,a LHM slab illuminated with a multiple cycle m-n-m pulses source is showed to have an obvious focusing effect,and can produce a perfect focus in and outside the slab under specific condition.