Inverse design based metamaterial concentrator and its applications and realization

Unlike the previous design method in which one must know the transformation function beforehand, an inverse design method is proposed to build a metamaterial concentrator in this paper. The required material parameters are independently obtained and expressed as functions of the introduced generator. Scattering magnifying ability of the concentrator and two applications for antenna miniaturization and military camouflage are also investigated. Moreover, to remove the anisotropic parameters and simplify the practical realization of the concentrator, a fan-shaped layered concentrator composed of only alternating isotropic materials is presented based on the effective medium theory. Full-wave simulation results are provided for verification. This work paves a new way for designing metamaterial devices without the need to know the underlying transformation function, and has great guiding significance for the fabrication and application of the concentrator. (C) 2015 Elsevier GmbH. All rights reserved.