The Application For Physical Optics And Iterative Accelerated Physical Optics Algorithms In Electromagnetic Scattering

The research on electrical large size scattering computing in complex enviroment has been a hot topic worldwide.To improve the efficiency of analysing electrial large size scattering,the PO?Physical Optics?for rough surafce scattering and IPO?Iterative Physical Optics?for strong coupling effect objects?such as,dihedral corner reflector,trihedral corner reflector?scattering are studied in this thesis.The preprocessing PO is initially proposed according to PO,the preprocessing PO improves the efficiency obviously and its improvement of efficiency will increase when the complutaion work grows.After comparing the preprocessing PO with CUDA?Computer Unified Device Architure?parallel computaing PO,the preprocessing PO is more competitive when the complutaion work is huge.Futhermore,in order to calculate the strong coupling effect object scattering,the IPO is studied and use the IPO to calculate the dihedral corner reflector,trihedral corner reflector and other strong coupling sactterers.The result shows that the IPO is applicable after compared with MoM?Method of Moment?,but owing to IPO is time-consuming when it deals with the electrical large size scattering,the Fast Multiple Method?FMM?is used in IPO.The IPO combined with the FMM makes the computational complexity changes from O?N²?toO(N^1.5),the computation efficiency is improved.The author's major contributions are as follows:1.Study the theory of PO and use PO calculate rough surface scattering.Research the terahertz scattering by PO and combine the theory and experiment,the result shows that the PO method is consistent with the experiment in reflect direction.Use the CUDA parallel technique to compute the rough surface scattering by PO,the result reaches to 8?compared with traditional method.2.After studying the PO method,the author finds that these factors affecting the scattering result are angle between incident direction and normal direction of facet,and phase of facet center position when the permittivity is constant,based on this,the preprocessing PO is rased.The method improves the calculation efficiency effectively,because it check the scattering result rather than calculate result.Accordind to the simulation result,the efficiency grows while the facet number increases.This new preprocessing PO opens a new way for other electromagnetic scattering methods to improve the calculation efficiency.3.Use the IPO to calculate strong coupling effect objects scattering and compare the result with MoM,it shows that the IPO is applicable.4.In order to reduce the computational complexity,use the FMM method to to accelerate the coupling percedure,after comparing the calculation time of IPO and IPO+FMM,the speed-up ratio will grow while the facet number increases.