  A new method to improve the accuracy and efficiency of characteristic mode
(CM) decomposition for perfectly conducting bodies is presented. The method
uses the expansion of the Green dyadic in spherical vector waves. This
expansion is utilized in the method of moments (MoM) solution of the electric
field integral equation to factorize the real part of the impedance matrix. The
factorization is then employed in the computation of CMs, which improves the
accuracy as well as the computational speed. An additional benefit is a rapid
computation of far fields. The method can easily be integrated into existing
MoM solvers. Several structures are investigated illustrating the improved
accuracy and performance of the new method.
