Based On Fast Direct Solution Of The Mda-svd-cbd

The multilevel matrix decomposition algorithm (MLMDA) was originally developed by Michielsen and Boag for 2-D TMz scattering problems and later implemented in 3-D by Rius et al. This paper will introduce matrix decomposition algorithm (MDA), such as the basic principle of equivalent and MDA-SVD.MDA-SVD is based on MDA algorithm singular value decomposition (SVD). MDA-SVD algorithm using green function based on the existing the method of moment (MoM) coding usually, this method has two advantages:on the one hand, a piecewiss smooth flat object is better than fast multipole effect,on the other hand it can overcome the disadvantages of multilevel fast multipole method(MLFMM), also can be used to analysis electromagnetic problem of multilayered medium.On the basis of MDA-SVD, this paper uses a new fast direct solution-compressed block decomposition algorithm (CBD) to solve the moment method (MoM) of electromagnetic radiation and scattering problem. The near field is directly computed, which is filled with full rank matrix.The interaction between far field and near field is not filled with full rank but sparse matrix. This method has two advantages:one is that it overcome the disadvantages of iterative method, the other is that when it calculate monostatic RCS, it cost very short time. For radiation and scattering problems in free space electromagnetic, the numerical complexity of CBD is shown to be O(N2)and the storage requirments is O(N3/2).After the CBD, we analyzed the basic principle and the operation steps of multilevel compressed block decomposition algorithm (MLCBD).For electrically large targets, the number of unknown is very large, The application of MLCBD will get higher efficiency than CBD.In order to use CBD better, we use an iterative method to improve the accuracy of result.After the compressed of CBD impedance matrix, when the precision of truncation is improved, it will reduce the time and memory, but it will make the result imprecise, at this moment using linear iterative method will improve the accuracy of the result. Finally the CBD is used for the precondition,which can improve the convergence condition. Keywords:The method of moment(MoM), compression block decomposition(CBD), multilayer impedance matrix decomposition(MLMDA)...