Research And Application Of Rapid Analysis Methods Based On Volume-surface Integral Equations

The efficient method of moment(MoM)is suitable for the analysis of electromagnetic scattering characteristics of electrically large targets.On the background of the MoM electromagnetic scattering analysis on composite targets,on basis of the adaptive cross approximation algorithm(ACA)and characteristic basis function method(CBFM),researches on the multi-angle scattering,the wide-band scattering and the acceleration techniques on iterative solution are carried out.The main research work is as follows.Firstly,using the fast adaptive cross approximation(FACA)algorithm to accelerate the multi-angle scattering characteristics analysis.The FACA is used to decompose and compress the excitation matrix which comes from the multi-angle incident plane waves,and the excitation matrix is presented as a decomposition form of three matrix multiplication.Then,the decomposition form is used and the matrix equation which is needed to solve is changed,so as to effectively reduces the times of MoM matrix equation solution.Secondly,using the reduced impedance matrices interpolation technique to calculate broadband monostatic RCS based on the ultra-wide band characteristic basis functions(UCBFs).The characteristic basis functions(CBFs)are extend to be the UCBFs based on the wavelets,and they are used to generate the reduced matrices on sampling frequencies.The reduced impedance matrices interpolation technique using a interpolation method to acquire the reduced impedance matrices of each analyzed frequency directly which improves the efficiency of matrix filling and further reduces the computation time.Thirdly,the sparsified adaptive cross approximation(SPACA)algorithm,which is optimized by the fast adaptive cross sampling(FACS),and the method mixed by characteristic basis function method(CBFM)and SPACA are used to accelerate the iterative solution.Among all low-rank decomposited alrgorithms,the SPACA has significant advantages on analysis of conducting targets within 50 wavelength.The SPACA is extend to analyze the electromagnetic property of composite targets.In addition,the SPACA is combined with the CBFM to further reduce the storage and computation time in view of the disadvantage of the SPACA.