Realization of negative refractive index with double-layered H-shaped resonator array

With an assembly of double-layered H-shaped metallic resonators, we simultaneously realized both magnetic and electric resonances at the same frequency band. Negative refractive index (NRI) is consequently achieved. The frequency band with NRI can be tuned by the structural parameters of the H-shaped resonators. This design demonstrates a unique example to construct metamaterial with NRI feature.