MULTILEVEL EVALUATION OF ELECTROMAGNETIC-FIELDS FOR THE RAPID SOLUTION OF SCATTERING PROBLEMS

A multilevel algorithm is presented for evaluating fields generated by given distributions of electric current. The algorithm can be used to accelerate the solution of scattering problems using the method of mo ments and/or boundary element methods. The algorithm exploits the limi ted number of degrees of freedom that characterize a field observed ov er a domain that is well separated from a source domain. Both the memo ry requirements and the computational complexity of the algorithm are O(N(s) log(N(s)), where N(s) is the common number of sources and obser vation points. The multilevel algorithm can easily be incorporated int o existing method-of-moments (MoM) programs. A simple physical interpr etation of the algorithm is provided. (C) 1994 John Wiley & Sons, Inc.