Metasurface-based ultrathin carpet cloak

Here we present the design and numerical results for an ultrathin unidirectional carpet cloak based on the restoration of the phase of the reflected wave. This ultrathin carpet cloak conceals a triangular surface bump with center height of 4.1 mm and tilt angle of 20 deg. The cloaking metasurface consists of an array of closed ring resonators, which allow an efficient phase manipulation along the edge of the bump. The numerical results at operation frequency f0 = 80 GHz demonstrate a good performance of the designed cloak in both near field and far field. The presented cloak has a thin, lightweight, and easy to fabricate design for radio and THz frequencies and can find applications in radar and antenna systems.