Comparison of two volume integral equation formulations for solving electromagnetic scattering by inhomogeneous dielectric objects

This paper presented two formulations of the electric field volume integral equation, and discussed the use of two different types of volume basis functions in the representation of the volume current. In conclusion, for the two types of volume basis functions, the solution accuracies are of the same order as long as the numbers of basis functions are comparable. The numbers of iterations of the C-type basis function are generally smaller than that of the D-type basis functions if the initial is a zero vector. For multiple incident angles, the D-type basis case needs slightly less number of iterations when the initial solution is predicted from the solution of the previous incident angle.