Research On Efficient Analysis Of Electromagnetic Scattering Characteristics Of Mixed Targets And RCS Reduction

In recent years,with the rapid development of science and technology,it is necessary to carry out electromagnetic modeling analysis for targets with complex structures in the fields of target detection and recognition,stealth and anti-stealth technology,radar system design and evaluation,and electromagnetic compatibility analysis.In response to this problem,this paper has deeply studied the method of moments of the volume surface integral equation and the efficient analysis method of electromagnetic scattering of mixed targets with arbitrarily complex structures and metallic medium.Aiming at the analysis of the electromagnetic scattering characteristics of metal-medium mixed targets,the volume surface integral equation method(VSIE)based on CRWG basis functions and CSWG basis functions is studied.First,the establishment of the surface integral equation(SIE),the volume integral equation(VIE)and the volume surface integral equation(VSIE)are systematically explained,as well as the numerical realization of the volume surface integral equation and the method of moments.In order to better fit the target and reduce the unknowns,the unknown currents in the discrete the volume surface integral equation of the CRWG basis function and the CSWG basis function based on the curved triangular element and the curved tetrahedral element are used.The discrete network of the CRWG basis function and the CSWG basis function must be a conformal network.However,when using a conformal network,the analysis of multi-scale targets may be difficult to achieve conformal network and cannot be solved.Therefore,for multi-scale targets,it is necessary to select a semi-basis function to describe the current of grid cells without common edges.Therefore,the volume surface integral equation based on the non-conformal network is studied,and the results of numerical examples are compared to verify its correctness.Furthermore,considering that there is a multi-scale structure for the target,the non-conformal volume surface integral equation method of moment has poor convergence and slow convergence in the calculation process,this paper studies the non-conformal volume surface integral equation domain decomposition method(VSIE-DDM).The domain decomposition method is based on the idea of divide and conquer to divide the target to be sought into several closed sub-regions,and the sub-regions are independently meshed with a certain size,which reduces the unknowns.In addition,in the calculation process,the original dense impedance matrix with a large order is transformed into a sparse matrix,and then the equation is solved,which will reduce the calculation time and improve the calculation efficiency.The results of numerical examples are compared to verify the correctness and efficiency of VSIE-DDM.For the stealth optimization design,it is actually a research on the reduction of the radar cross section(RCS).This paper is based on the domain decomposition method of non-conformal volume surface integral equation,genetic algorithm(GA)is added,and the optimization problem of RCS for metal-medium mixing targets is studied.The main method used is to optimize the parameters of the coating material.The results show that the RCS of the metalmedium mixing target before and after the optimization is reduced within a certain range,and the reduction of the RCS is realized.The research work in this paper provides an effective solution for the efficient analysis of the electromagnetic scattering problem of metal-medium targets and the reduction of RCS.The results of numerical examples have verified its correctness and efficiency,and laid a solid method foundation for further analysis of electromagnetic problems in actual engineering.