Efficient Scattering Calculation Model for Electrically Large Targets Coated With Phase-Modulated Metasurfaces

Metasurface, consisting of subwavelength cells arranged in a periodic pattern, has emerged as a promising structure for controlling the scattering. However, studies in this field have primarily focused on the electromagnetic characteristic of metasurface itself. There are few studies on developing computational models for the scattering characteristic of electrically large target coated with metasurfaces. In this article, a scattering characteristic calculation model is proposed for such target, in which the metasurfaces are treated as rectangular electromagnetic surface radiators. Based on a rectangular plate scattering model and high-frequency approximation theory, the field of metasurface cell and homogeneous material cell is derived. Then, the total scattered field can be obtained by summing up the field of all the cells. Our simulation results demonstrate that the proposed model offers accurate scattering characteristic of electrically large target coated with phase-modulated metasurfaces. In addition, the echo and synthetic aperture radar (SAR) images of targets coated with metasurfaces are simulated, providing the intuitive variation of scattering characteristic. This article offers a theoretical foundation and practical guidance for the design and optimization of metasurfaces based on demand, which have potential applications in diverse areas, such as radar, communication, and sensing.