Study on the scattering property of square patch gradient index metasurfaces

Square patches with different sizes are used to construct gradient-index meta-surfaces in this paper, and the scattering properties of the surfaces are studied. Two types of the gradient-index surface are discussed, one is designed for transforming incident wave to surface wave, and the other is designed for reflecting incident wave to scattering wave to a fix direction in far field. The backward RCSs of these two kinds of surfaces are reduced 16 dB and 8 dB respectively. The scattering properties are further analyzed by transforming the E-fields above the surfaces into K-space, and the propagation constants of the waves bounded on the surfaces are discussed.