We investigate three-dimensional left-handed and related metamaterials based on a fully symmetric multigap single-ring split-ring resonator (SRR) design and crossing continuous wires. We demonstrate isotropic transmission properties of a SRR-only metamaterial and the corresponding left-handed material that possesses a negative effective index of refraction due to simultaneously negative effective permeability and permittivity. Minor deviations from complete isotropy are due to the finite thickness of the metamaterial.

• Received 10 December 2004

DOI:https://doi.org/10.1103/PhysRevB.71.121103