Power flow for resonance cone phenomena in planar anisotropic metamaterials

Abstract

The metamaterial considered is a planar wire-grid network loaded with closely spaced, orthogonal capacitors and inductors, positioned over a ground plane and parallel to it. Excited by a single-frequency point source, this metamaterial exhibits conical high-field regions called "resonance cones" which extend outward from the source in directions predetermined by the load reactances, thus carrying RF power to specific points on the resistively terminated network edges. When two such metamaterials are interfaced, the cones traversing the interface can exhibit negative refraction as well as subwavelength focusing, phenomena supported by physical experiments and corresponding moment-method simulations. Poynting vector calculations based on the simulation data reveal power flow that follows the cones smoothly from the source and across the refraction interface. Electromagnetic field and Poynting vector calculations both exhibit potentially significant differences depending on whether they are done at the ground plane level or at the level of the anisotropic grid.