A concise and practical domain decomposition method using phase extracted basis functions

A domain decomposition method (DDM) using phase extracted basis functions with very few overlapped buffer regions is investigated to solve electromagnetic scattering problems of electrically large PEC objects. The concept of "Non-scattering surface" is employed in this DDM and combined field integral equation (CFIE) is used in the numerical solution of each subdomain in corresponding local model which can be seen as a closed object. Instead of employing a certain number of basis functions as buffer regions, this method just uses the patches adjacent to artificial boundaries to ensure the normal continuity of the currents across the artificial regional edges. The multilevel fast multipole algorithm (MLFMA) is applied to accelerate the computation of matrix-vector multiplication. Numerical results show that with buffer regions mentioned above, using phase extracted basis functions defined on large patches has better convergence rate than RWG or CRWG basis functions.