Extraction of effective constitutive parameters of active terahertz metamaterial with negative differential resistance carbon nanotubes
基于负微分电阻碳纳米管的太赫兹波有源超材料特性参数提取

A strategy is presented to acquire active terahertz (THz) metamaterial by incorporating negative differential resistance carbon nanotubes. Furthermore, we propose a method of extracting active metamaterial effective parameters. This new method can effectively solve the problems of signs and multi-branches, while the traditional parameter extraction method becomes powerless for active case. Our results indicate that the active THz metamaterial with metal wires array not only has negative value of the imaginary part of the permittivity but also presents magnetic-dispersion characteristics.