Metamaterials with broadband double negative characteristics based on mie resonance

A broadband double negative media (DNG) is proposed and investigated theoretically in this paper. The top view of structure proposed in this paper is a combination of ellipses with minor axis at 6 mm and major axis at 16 mm, rotating 45 degrees each time. The combination of ellipses is a gradient structure at the boundary, so that there are strong superposition of coupling between each two ellipses which leads to broad the bandwidth of DNG. With the full wave simulation software CST, S11 and S21 are obtained. Afterwards, by using Nicolson-Ross-Weir (NRW) inverse method, permittivity and permeability are derived and the bandwidth for DNG is 52.17%, from 3.4 to 5.8 GHz. The structure is easy to manufacture as a result of its plane structure. It is believed that this result will accelerate the use of DNG.