The SSOR-preconditioned inner outer flexible GMRES method for the FEM analysis of EM problems.

When solving electromagnetic problems by finite element method, the resulting linear systems are ill-conditioned when the PML absorbing layers are adopted. Traditional Krylov iterative algorithms usually converge slowly or may even stagnate. In this paper, the combination of the inner–outer Flexible Generalized Minimum Residual Method (GMRES) and the symmetric successive overrelaxation (SSOR) preconditioning scheme is used to accelerate the iteration for solving a large sparse system of linear equations resulting from the analysis of EM problems by use of edge-based finite element method (FEM). The numerical results show that tens of times convergence improvement can be achieved compared with the conventional GMRES solver. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1708–1712, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21758 [ABSTRACT FROM AUTHOR]