Design of Artificial-Material-Based Antennas Using Inverse Scattering Techniques

A new approach to the design of graded artificial materials (GAMs)-based devices is proposed by exploiting the inverse scattering framework as a synthesis tool. The introduced general methodology can be applied to arbitrary far-field specifications, thus allowing the design of noncanonical devices. In particular, two different strategies are developed for GAMs based on either graded refractive index (GAM) or graded filling factor (GAM). In both strategies, the inverse scattering problem is solved by a proper reformulation of the contrast source inversion method, wherein a proper rescaling of the amplitude of the primary sources is also used. In particular, in the first strategy, the GAM is obtained by exploiting homogenization theories. In the second strategy, the GAM is synthesized by exploiting a suitable representation basis for the unknown contrast function, and then simple analytical formulas are used to determine the corresponding GAM. The proposed approach is assessed through the synthesis of an antenna generating a ?/? reconfigurable pattern.