Contents I. Introduction
Recently, revolutionary results have been obtained in the field of metamaterials, artificial structures that exhibit electromagnetic properties generally not found in nature. Metamaterials are designed using sub-wavelength particles, whose size is typically smaller then one-tenth of the propagating signal wavelength. Due to this fact, quasi-static analysis can be performed and the concept of artificial effective media can be applied. the structures obtained using this approach can be considered as a continuous medium with effective parameters, namely, effective dielectric permittivity and effective magnetic permeability. By a proper choice of the type and geometrical arrangement of constituent sub-wavelength particles, the effective parameters of metamaterials can be made arbitrarily small or large, or even negative.
