Numerical investigation of the accuracy and efficiency of integral formulations in electromagnetic field problems of near metallic objects scattering

The paper considers the problem of electromagnetic field scattering from a metallic object. Tangential, normal and combined integral formulations are realized. Based on a general theoretical analysis, numerical studies of integral formulations have been carried out. Accuracy and effectiveness, as well as other features and limitations in the numerical solutions of the scattering problem were demonstrated. Special attention is paid to the analysis of the integral formulation accuracy in the scattered electromagnetic field determination near a scattering object. This analysis was carried out using the problem of an electromagnetic field scattering on a metallic sphere. The numerical and analytical solutions were compared. In particular, it is shown that the tangential formulation of the integral equation of the electric field provides the best accuracy in the scattered field determination in the near field, and it is preferable for use in the design of metallic structures with the required level of reflections. At the same time, the combined integral formulation makes it possible to provide an optimal solution to the scattering problem with respect to the “accuracy – time” criterion. This is relevant in the case of an object of large electrical size.