A fast analysis of microwave devices by the combined unifrontal/multifrontal solver for unsymmetric sparse matrices

The multifrontal method is applied for solving a large, sparse, and unsymmetric system of linear equations resulting from the use of the edge-based finite-element method (FEM). The finite-element method combined with perfectly matched layers (PML) is given for simulation of microwave devices, and the combined algorithm of the multifrontal method is described. The electrical characteristics of typical waveguide devices such as the ferrite phase shifter and circulator are analyzed, and the calculated results are compared with those obtained from the literature. In order to demonstrate the efficiency of the multifrontal method, the computational time is compared with that of both successive overrelaxation (SOR) preconditioned conjugate-gradient (PCG) and conjugate-gradient methods (CG) for the phase shifter.