Azimuthally Inhomogeneous Metasurface Cloak for Cylindrical Objects

An analytical formula to define an azimuthally inhomogeneous metasurface (AIM) cloak for cylindrical objects is presented. The inhomogeneity of the metasurface is modeled by Fourier decomposing the azimuthally varying susceptibility distribution. The AIM cloak provides weighted control on each scattering mode to enhance the scattering reduction capability for prescribed incident angles of interest. With an AIM cloaking layer, the scattering reduction of a 0.15-wavelength radius metallic cylinder can be enhanced by more than 6 dB compared to a conventional homogenous metasurface cloak. Accuracy of the formulation is proven with full-wave simulations. The design of the AIM cloak is experimentally validated at four bistatic angles.