Efficient Iterative Solution of Combined Source Integral Equation Using Characteristic Basis Function Method With Initial Guess

Using only the RWG functions, the combined source integral equation (CSIE) with weak form combined source condition can achieve fine accuracy and fast iterative convergence for conductor objects. However, compared with a conventional integral equation in the method of moments (MoM), the conventional CSIE involves more matrices and more complex numerical processing, and these make the CSIE inefficient, especially for multiple excitation problems. In this article, a characteristic basis function (CBF)-based CSIE with initial guess is proposed to mitigate this problem. The CBF is employed to reduce the number of unknowns as well as the storage consumptions and iteration time. In the meantime, an initial guess especially for CBFs is proposed to reduce iterations when solving multiple excitation problems. Numerical results are given to demonstrate the performance of the proposed method.