Ultrathin metasurface coatings for near-perfect electromagnetic cloaking and illusion beyond the quasi-static limit

In this paper, a low-profile, low-loss electromagnetic cloaking and illusion coating technique is introduced based on single-layer anisotropic metasurfaces for cylindrical objects with moderate sizes beyond the quasi-static limit. In contrast to previous work on metasurface cloaks, coatings with non-vanishing radial response are employed here, which can be accounted for by the second-order surface impedance boundary condition and also be tailored to control higher order scattering modes. It is shown through both analytical solutions and full-wave numerical simulations of realistic coatings comprised of discrete metasurfaces that near-perfect cloaking and illusion can be achieved for a moderate-sized conducting or dielectric cylinder. This work will serve to broaden the usage of metasurfaces to applications ranging from scattering reduction/deception to noninvasive probing for objects beyond the quasi-static limit.