Uncertainty RCS Computation for Multiple and Multilayer Thin Medium-Coated Conductors by an Improved TDS Approximation

An efficient uncertainty RCS computation technology is proposed to analyze the EM scattering from 3-D medium-coated targets with varying geometrical shapes. First, the scattering target is described by a nonuniform rational B-spline surface, where the uncertain units are described by several independent random variables. Then, an improved thin dielectric sheet-based method of moments is presented to model the scattering from the multiple and multilayer thin medium-coated objects. As a result, only unknowns exist on the target's outer surface, and the computational resources can significantly be saved in comparison with solvers that associate unknowns with all the surfaces and interfaces. It should also be noted that the half RWG basis functions are introduced at the interface of different media for multiple medium-coated conductors. Finally, both the mean value and variance of the scattering electric current are derived by applying a perturbation approach to account for the target's uncertain variable geometry. Moreover, the validity of the proposed method is verified in comparison with the traditional Monte Carlo (MC) method, which is used to solve several certain problems, and it is found that the proposed method can provide higher efficiency compared with the MC method.