Diffraction of nonuniform electromagnetic beams at a slab of metamaterial

A plane-wave expansion method is used to analyze the interaction of nonuniform electromagnetic waves with a metamaterial slab. A network of transmission lines models the propagation of the constituting plane-wave components of the incident and diffracted beams. Having determined the complex amplitude of these components, one can obtain the total solution using superposition. The obtained simulation results demonstrate the negative refraction phenomenon and focusing effect in a metamaterial slab. The results show very good agreement with those reported in the literature using fully numerical methods. Since the approach is semi-analytical, it is not only more precise than purely numerical methods, but also demands minor computational resources.