Calculation of Far-Field Scattering from Nonuniform Reflective Metasurfaces: A Critical Perspective

To design and characterize radio environments with metasurfaces, it is necessary to know the scattering properties of finite-size anomalously reflecting (phase-gradient) metasurfaces. Recently, different approaches have been proposed to tackle this problem. In this presentation, we will present a comparison between alternative analytical models. We will first derive a general formulation for the far-field scattering by reflective metasurfaces based on the Huygens principle. Then we will specify the assumptions of known models. The first model that we will study is based on the assumption that at each point of the metasurface the reflected field equals the incident field multiplied by a controllable reflection coefficient. Then we will analyze the same structure with an analytical model based on the use of macroscopic reflection coefficients following the theory of diffraction gratings. Finally, we will numerically analyze the structure and compare the results.