Experimental Verification of the Behavior of a Double Negative Metamaterial Composed of Planar Resonant Elements

Measurement of the behavior of double negative volumetric metamaterials is presented in this paper. These metamaterials are composed of planar resonant elements that show negative electric and magnetic polarizabilities. The first metamaterial is a regular 3D periodic structure. The second metamaterial is an analog of an amorphous solid material. The resonant elements are randomly located in space, both in their positions and in their orientation. Planar resonators are inserted into polystyrene spheres to assure their fully random distribution in the space. This has the advantage that the spheres can fill any volume keeping a random distribution of resonant particles. This composite material shows an isotropic response, as it does not prefer any direction of wave propagation. The measurements verified that metamaterials of both types behave as a double negative metamaterial within a narrow frequency band.