Metamaterials with near-zero refractive index produced using fishnet structures

Metamaterials with near-zero refractive index designed using fishnet structures are proposed. The near-zero-index band is generated with the overlap of electric and magnetic resonances, where the transition from a negative-n region to a positive-n region is found. Both the permittivity and the permeability are controlled via geometrical parameters and the structure orientation, and are near-zero within the operating band, resulting in low loss transmission. As the number of layers increases, the transmission band becomes broader and moves to lower frequency. The experimental results confirm that such designs can generate a near-zero refractive index with low loss within an operating frequency band.