Multilevel MDA-CBI for fast direct solution of large scattering and radiation problems

This paper presents the multilevel MDA-CBI method for accelerated direct solution of scattering and radiation problems with the method of moments. The method has all the advantages of a direct solution (no convergence issues, very little marginal cost per excitation vector). For a medium size problem of about 70.000 unknowns it performs some 25 % better than the one level algorithm, but this advantage is expected to grow for larger problems since the computational complexity is considerably better, with a theoretically attainable value of N^5/3log²N.