电磁波与双负介质板相互作用的FDTD分析

FDTD Analysis on the Interaction between Electromagnetic Wave and Double-Negative Metamaterials

由双负介质本够关系出发,将其相对磁导系数表示为以jω为自变量的Padé近似形式,利用时频转换关系jω→/t,引入离散时域移位算子代替时间微分算子,推导出FDTD计算双负介质的递推表达式。针对双负介质的电磁特性问题,用基于移位算子的FDTD方法研究了电磁波与各种双负介质的相互作用:会聚效应、相位补偿、高指定向性、减小金属后向散射,探讨双负介质在平板成像、谐振腔、天线、隐身方面的应用前景。

Based on the constitutive relation of double negative （DNG） metamaterials, the permeability of DNG media is described by Padé approximation in jω. By introducing the transform relation connecting time domain and frequency domain and zt defined as a shift operator, the formulae of the shift operator method in Finite-Difference Time-Domain （FDTD） method is derived. According to the electromagnetic （EM） characteristic of DNG media, the interaction between EM wave and DNG media such as foci effect, phase compensation, directive emission, decreasing backward scattering is studied with FDTD method. The applications of DNG media in fiat plate imaging, resonator, antennas and shielding are discussed.