Volumetric Double Negative Metamaterial Composed of Planar Resonators

This paper investigates double negative volumetric metamaterials. The first version is a regular 3D periodic structure. This metamaterial does not naturally show an isotropic response. An isotropic response has been obtained for an analog of an amorphous solid material. This metamaterial is composed of planar resonant particles that show negative electric and magnetic polarizabilities. The particles are randomly distributed in space both in their positions and in their orientation. This composite material shows an isotropic response, as it does not prefer any direction of wave propagation. The metamaterial was assembled by inserting planar resonators into polystyrene spheres. The advantage is that the spheres can fill any volume and assure a random distribution of resonant particles both in space and in orientation.