A 3D isotropic left-handed metamaterial composed of wired metallic spheres

A novel structure supporting three-dimensional (3D) negative refractive index are proposed. The 3D structure is composed of an array of metallic spheres arranged in the face-centered cubic (fcc) lattice configuration as in natural molecules, and all the spheres are wired at the center of the lattice. The structure is simple and scalable in frequency. In order to study the wave propagation in the structure, full-wave simulations using HFSS® are carried out. The dispersion characteristics of the structure clearly show that the structure supports left-handed waves as the dominant mode not only in orientation directions but also in the diagonal directions. Parametric studies of the isotropy and homogeneity enhancements on the structural parameters are also carried out to reveal the relation between the structural parameters and the dispersion characteristics.