Improving the integral equation in the hybrid FEM-RBCI method for scalar electromagnetic problems

Purpose – The purpose of this paper is to improve the accuracy of the integral equation of the hybrid FEM-RBCI (Finite Element Method-Robin Boundary Condition Iteration) method for the numerical solution of two-dimensional electromagnetic (or acoustic) scattering problems. Design/methodology/approach – This accuracy improvement is achieved by selecting the integration curve as straight segments lying in the middle of the triangular finite elements. An accuracy improvement is obtained as compared with selecting the integration curve as constituted by element sides. Findings – The improved FEM-RBCI method described in this paper leads to accuracies of the numerical results which are better than those obtained by selecting the integration curve by element sides. Originality/value – The paper presents results for a simple two-dimensional structure: a dielectric circular cylinder.