Radar Cross Section (RCS) analysis of Finite Metamaterial Based Absorber for Planar and Curved Configurations

In this paper, a finite planar FSS (frequency selective surfaces) based absorber structure is analyzed in terms of its radar cross section under plane wave incidence and compared with the corresponding unit cell design with periodic boundary conditions. It is observed that the performance of finite absorber structure deteriorates under oblique incidence of plane waves. This observation is further supported by analyzing the scenario when a planar structure is bent around a cylinder and in the process, a limit of conformability is defined. This provides the maximum allowable curvature (or upper limit of bent angle) beyond which the planar absorber, designed based on unit cell simulations, cannot be used for conformal applications. These observations are supported by scattering analysis of bent absorber for three different radii of curvature, in Ansys HFSS.