Calculation Of Wideband Electromagnetic Scattering Based On Equivalent Principle Algorithm

With the development of modern military science and technology,the target objects studied in the actual project has become more and more complex.At the same time,it also increases the requirements for the performance of the radar system.How to obtain target information quickly and effectively has been become a hot research topic among modern scholars.In the international field,the powerful military weapons can better protect the sovereignty and territorial integrity of their own countries,especially stealth and anti-stealth technology,which are the key topics of various countries.Stealth and other technologies all involve the calculation of electromagnetic scattering properties over a wide frequency band.It can be seen that wideband research has reached an important stage.First of all,the method of Moments(Mo M)in the analysis of electromagnetic problems is the accurate solution,so it has been widely used analyzing electromagnetic scattering and radiation problems.However,when calculating the electromagnetic properties over a wide frequency band,the method of Moments calculates the frequency points one by one to obtain the solution within the whole bandwidth.This method will lead to a rapid increase in the amount of calculation.In order to effectively calculate the problem of wideband electromagnetic properties,this article introduces frequency and material independent reactions for method of Moments(FMIR-Mo M),whose basic idea is to expand the Green's function in free space by taylor series,extract and calculate the frequency-independent part separately,and then multiply it by the phase factor matrix containing the frequency,thereby improving the frequency sweep efficiency.Next,the paper elaborated the derivation process of FMIR-Mo M based on the electric field integral equation and magnetic field integral equation.Final y,the accuracy of the FMIRMo M algorithm are verified through calculation examples.The data results show that the calculation results of FMIR-Mo M and Mo M are completely fitted.Compared with Mo M,the calculation efficiency of FMIR-Mo M is improved by 13-22 times.With the increase of computing bandwidth,the computing efficiency will be significantly improved.Therefore,the advantages of FMIR-Mo M algorithm are obvious in the calculation of the electromagnetic properties over a wide frequency band.Secondly,when we analyze the wideband electromagnetic scattering problem of complex structure and periodic array structure,due to the huge number of unknown amount of calculation target,the computer memory required for FMIR-Mo M calculation increases greatly,and the calculation efficiency will also decrease.In addition,most of the actual electromagnetic problems have multi-scale characteristics.In order to solve this problem,we first proposed the combination of frequency and material independent reactions(FMIR)and tangent equivalence principle algorithm(TEPA)based on domain decomposition method to analyzed the wideband electromagnetic scattering properties of complex structures and periodic array structures.In this paper,the realization process of FMIR-TEPA computing single structure and multiple target structures was deduced in detail.Final y,the accuracy and feasibility of the FMIR-TEPA algorithm are verified through calculation examples.The calculation example compares the calculation results of FMIR-TEPA and Mo M.The data results show that the calculation results of the two are completely consistent.At the same time,we compared the calculation efficiency of Mo M,FMIRMo M and FMIR-TEPA in the calculation of complex target array structure.The data results show that compared with FMIR-Mo M,the computer memory of FMIR-TEPA has been effectively reduced;compared with Mo M,the calculation efficiency of FMIR-TEPA is increased by 26 times.With the increase of array structure,the computing efficiency will increase,and the advantages of FMIR-TEPA algorithm will become more and more obvious.