A relaxed iterative domain decomposition method with multifrontal algorithm for waveguide problems

The domain decomposition method (DDM) is an efficient method for analyzing electrically large and complicated electromagnetic problems. An iterative DDM algorithm is widely used for static electromagnetic problem. However, for electro-dynamic problems, its use cannot be ensured. For waveguide problems, the fictitious boundary condition (FBC) is used to divide the computational domain. We present an absorbing FBC, which includes higher order modes, and generate an iterative DDM algorithm. The relaxed algorithm is introduced to improve the iterative convergence efficiently. Matrix equations are solved using the multifrontal algorithm to reduce CPU times greatly. A rectangular waveguide with an E-plane discontinuity is analyzed. A number of numerical results are given to illustrate its accuracy and efficiency.