Study On The Electromagnetic Scattering From Rough Surface Based On The Single Integral Equation

As one of the classical algorithms,the method of moments(MoM)is widely used to study the electromagnetic(EM)scattering from rough surface due to its accuracy.When the MoM is applied to simulate the EM scattering from a dielectric rough surface,the induced electric current and the induced magnetic current will flow along the rough surface at the same time.The induced electric current and the induced magnetic current make the simulating of the EM scattering from dielectric rough surface more complicated.Moreover,there are many unknowns in the actual EM scattering from a dielectric rough surface.The full rank matrix formed by the MoM needs large memory and takes a long time.In this thesis,the single integral equation(SIE-MoM)is proposed to simulate the EM scattering from the dielectric rough surface.In the SIE-MoM,the complexity generated by the induced electric current and the induced magnetic current is avoided.And the number of the unknowns of the SIE-MoM is only half of the traditional MoM.Moreover,the SIE-MoM is combined with the characteristic basis function method(CBFM)or the adaptive modified characteristic basis function method(AMCBFM)to further improve the efficiency in this thesis.The dimension of the direct matrix is reduced by controlling the size of the discrete subdomain.Main works of this thesis are as following:1.The basic theories of simulating the EM scattering from a one-dimensional PEC rough surface or dielectric rough surface by the traditional MoM are given in detail.The detailed derivation process of the electric field integral equation and the magnetic field integral equation are shown.And the influences of the root mean square height and the correlation length on the EM scattering are analyzed.2.The complex functions are generated in simulating the EM scattering from a dielectric rough surface by the traditional MoM.The SIE-MoM is proposed to avoid the complex function.And the theoretical formulations of the SIE-MoM for simulating the EM scattering from the dielectric rough surface are exhibited.The accuracy and the validity of the SIE-MoM are shown by comparing the simulations of the SIE-MoM with the results of the traditional MoM.3.The mathematical principle of the CBFM is given.And the CBFM is combined with the SIE-MoM.The dielectric rough surface is discretized into several subdomains.By the CBFM,a reduced matrix with only partial subdomains is formed.The accuracy and effectiveness of the SIE-CBFM are given by comparing with the simulations of the SIE-MoM and the traditional MoM.4.The mathematical principles of the AMCBFM are shown.And the SIE-MoM is combined with the AMCBFM to further fast simulate the EM scattering from the dielectric rough surface.The accuracy and the validity of the SIE-AMCBFM are given by comparing with the simulations of the SIE-MoM and the traditional MoM.