New Metrics for Artificial Magnetism from Metal-dielectric Metamaterial Based on The Theory of Characteristic Modes

In this letter, new metrics are proposed to provide physical insight into the behavior of metamaterial based structures by means of the theory of characteristic modes. A relationship between the first eigenmode and an expression of the polarizability is proposed for a split ring resonator. It thus allows us to describe a link between the artificial magnetic response of a split ring resonator and modal characteristics. Using the new metrics proposed, a reactive impedance substrate based on metal-dielectric metamaterial excited by a parallel magnetic field is shown to exhibit artificial magnetism. These metrics are shown to propose good agreement with other analytical and numerical methods. This analysis should be useful when such metal-dielectric metamaterial structures are associated to radiating elements like antennas, since it could be performed in the near field region, unlike common approaches based on plane wave and far field assumptions.