Resonance Cone Formation, Reflection, Refraction, and Focusing in a Planar Anisotropic Metamaterial

The material studied is a planar wire-grid network loaded with orthogonal capacitors and inductors. Over a ground plane and excited by a localized single-frequency source, this metamaterial exhibits conical high-field regions called resonance cones. The cones exhibit specular reflection from boundaries and, with two such materials interfaced, the cones exhibit negative refraction as well as subwavelength focusing into a spot smaller than 1/20th of a free-space wavelength. Moment-method simulations and experiments show good agreement.