Research On Fast Calculation Of The Monostatic RCS Of Electrically Large Objects Based On Improved Characteristic Basis Function Method

The electromagnetic scattering characteristics of targets as the information source of radar detection,identification and tracking has been a hot topic in the field of computational electromagnetics.How to effectively obtain it has also been widely concerned by researchers.Based on the characteristic basis function method(CBFM),this paper puts forward some improvement measures to achieve the solution of monostatic radar cross section(RCS)quickly.Firstly,this paper introduces the basic principle of the method of moments(MOM).Then the CBFM is introduced.According to the different ways of characteristic basic functions(CBFs)construction,the CBFM can be divided into three types.Among the three types,the CBFM which is based on the singular value decomposition(SVD-CBFM)is suitable for the computation of monostatic RCS of targets as the CBFs and reduced matrix can be reused.So in this paper,some improvement measures are proposed on the basis of SVD-CBFM.The SVD-CBFM requires a large number of incident plane waves to excite each sub-field when constructing CBFs,which results in a large number of CBFs and causes time-consuming in the singular value decomposition.Besides,this method does not takes into account the redundant information existing in the excitation and ignores the influences of mutual coupling among sub-domains which will influences the improvement of the calculation accuracy.In order to alleviate these problems,an improved characteristic basic function method(ICBFM)is proposed.Firstly,the improved method considered redundant information that exist in the excitation and used the singular value decomposition to remove the redundancy.Then the couple effects among the blocks are fully considered and the secondary level characteristic basic function are used to enhance the calculation accuracy.In order not to increase the number of CBFs,an improved characteristic basis function is constructed by mathematical transformation.Since the improved basis function contains the information of the secondary level characteristic basic function,the number of CBFs will not increased and the the accuracy of the calculation will be improved.Finally,in order to further save the calculation time,some accelerating techniques are introduced to combine with the improved characteristic basis function method which will effectively improve the efficiency of the solution.