UAPO based Diffraction Coefficients for Lossless Double-Negative Metamaterial Slabs

An approach for evaluating the field diffracted by the edge of a lossless and isotropic double-negative layer illuminated at normal incidence by a plane wave is here proposed. The key point is the use of a physical optics approximation for the equivalent electric and magnetic current densities in the radiation integral. Then, a useful approximation and a uniform asymptotic evaluation of such an integral allow one to obtain the two-dimensional diffraction coefficients. The here proposed solution results to be efficient and simple to implement in a computer code and can be surely useful in all the applications wherein the truncation effects in double-negative metamaterials cannot be neglected.