Anisotropic Mantle Cloaks for TM and TE Scattering Reduction

We present the design and realization of anisotropic mantle cloaks operating, at the same frequency, for both TM and TE incident polarizations. Starting from the analytical model of metasurfaces available in the literature, we first explore the potentials and limitations of the most common metasurface geometries for their application as mantle cloaks. Then, we introduce new types of patterned surfaces aimed at improving their polarization response. We demonstrate that, only by using four metasurface topologies, it is possible to obtain all required combinations of positive and negative reactance values in order to design effective mantle cloaks for planar, cylindrical, and three-dimensional (3-D) objects. We also show that the accuracy of the analytical formulas commonly used to design such metasurfaces is not necessarily sufficient for cloaking purposes. Therefore, we introduce and validate a numerical procedure to refine the analytical design and optimize the cloak performance. The effectiveness of the designed covers is checked with full-wave simulations. Finally, some antenna applications of dual-polarized mantle cloaks are proposed and several experimental measurements conducted on fabricated prototypes are also provided.