Double negative medium composed from two split ring resonators

A new type of double negative medium(DNG) is proposed, which is made of two split ring resonators and has a simple structure. The numerical simulation of the new DNG is studied by using FDTD method and CST software, the physical mechanism of this structure is analyzed and its double negative effect is illuminated. Finally, the inversion scheme, which is the extension of commonly used Nicolson-Ross-Weir method, is deduced to obtain the constitutive parameters of the double negative medium in a waveguide. The extraction of its constitutive parameters shows that the real parts of the effective permittivity and permeability of this new type of DNG are both negative at frequency 10.3 GHz and its vicinity,which confirms its double negative effect．