Comparison of Characteristic about Absorbing Electromagnetic Wave between Double-Negative Metamaterials and General Dispersive Media

Soviet scientist Veselago [1] indicated in 1968 that media with negative permittivity and permeability would have distinct electromagnetic characteristic. In 2001, Inspired by the work of Pendry et al., Smith et al. constructed a composite "medium" in the microwave regime by arranging periodic arrays of small metallic wires and split-ring resonators. This media can also be mentioned double-negative (DNG) metamaterials, Since then, various ideas and suggestions for potential applications of metamaterials have been mentioned. In this paper, First, Lossy Drude polarization and magnetization models [2] are used to simulate the DNG media. The time domain equations solved with the finite-difference time-domain method (FDTD) simulator for the matched DNG media are presented. The discretized E_z and J_z of TM case in the 2D-FDTD simulators are given. Second, by comparing with the result in reference [2], the paper\´s method and program are validated. The broadband backward scattering of metallic column covered by different media layer is given in fig. 1. Because of DNG media\´s impedance matched to free space, its character of absorbing electromagnetic wave is better than general dispersive media. From fig.2, one finds that when DNG media\´s depth d, plasma frequency omega_p and damping frequency increase, the Radar Cross Section decrease in quite broad frequency bands. The bigger DNG media\´s plasma frequency and damping frequency, the higher the best absorbing frequency band is.