Regularization of the moment matrix solution by a nonquadratic conjugate gradient method

Inspired by Tikhonov regularization, a nonlinear conjugate gradient method is proposed with the purpose of simultaneously regularizing and solving the moment matrix equation. The procedure is based on a nonquadratic conjugate gradient algorithm with exact line search, restart, and rescale. Applied to the problem of TM scattering by perfectly conducting rectangular cylinders, the method is shown to exhibit a fast convergence rate.