NEGATIVE REFRACTION OF CHIRAL METAMATERIAL BASED ON FOUR CRANK RESONATORS

Here we present the experimental characterization of a new material constituted by an array of four same handedness three-dimensional cranks impressed on a dielectric substrate. Using a free-wave experimental set up, the transmission and reflection coefficients were measured, and effective values for the refractive index, permittivity and permeability, and chirality parameter were calculated. The material exhibits a high electromagnetic activity and relatively low refractive index; the joined effect of both factors results into negative values for the refraction index for one of the two circular eigenmodes in a 0.4 GHz bandwidth above the resonance frequency.