Fast convergence of MoM-based package-board extraction via incremental eigen-AGMRES method

3D full-wave extraction of electronic systems using fast Method of Moments is often bottlenecked by the convergence of the Krylov-subspace based iterative process. For example, the Electric Field Integral Equation (EFIE) matrix often exhibits bad spectral properties which render iterative solvers slow to converge or stagnate occasionally. In this paper, an Augmented Generalized minimal residual (AGMRES) method is employed to expedite the convergence of matrix solution at a specific frequency by extracting and applying eigen vectors from a previously solved frequency. Numerical results demonstrate up to 40% improvement in the convergence properties using the proposed AGMRES method.