Green’s Function Integral Equation Methods for Electromagnetic Scattering Problems

2018 ◽  
pp. 197-250
Author(s):  
Andrei V. Lavrinenko ◽  
Jesper Lægsgaard ◽  
Niels Gregersen ◽  
Frank Schmidt ◽  
Thomas Søndergaard
Keyword(s):  
Integral Equation ◽  
Green’S Function ◽  
Green's Function ◽  
Electromagnetic Scattering ◽  
Scattering Problems ◽  
Integral Equation Methods

The efficient implementation of IE-FFT algorithm with combined field integral equation for solving electromagnetic scattering problems

2020 ◽  
pp. 1-7
Author(s):  
Seung Mo Seo
Keyword(s):  
Integral Equation ◽  
Green’S Function ◽  
Green's Function ◽  
Electromagnetic Scattering ◽  
Cartesian Grid ◽  
Memory Storage ◽  
Scattering Problems ◽  
Cpu Time ◽  
Interaction Terms ◽  
Field Integral

Abstract An integral equation-fast Fourier transform (IE-FFT) algorithm is applied to the electromagnetic solutions of the combined field integral equation (CFIE) for scattering problems by an arbitrary-shaped three-dimensional perfect electric conducting object. The IE-FFT with CFIE uses a Cartesian grid for known Green's function to considerably reduce memory storage and speed up CPU time for both matrix fill-in and matrix vector multiplication when used with a generalized minimal residual method. The uniform interpolation of the Green's function on an equally spaced Cartesian grid allows a global FFT for field interaction terms. However, the near interaction terms do not take care for the singularity of the Green's function and should be adequately corrected. The IE-FFT with CFIE does not always require a suitable preconditioner for electrically large problems. It is shown that the complexity of the IE-FFT with CFIE is found to be approximately O(N1.5) and O(N1.5log N) for memory and CPU time, respectively.

scholarly journals Fitting Green’s Function FFT Acceleration Applied to Anisotropic Dielectric Scattering Problems

2015 ◽  
Vol 2015 ◽  
pp. 1-8
Author(s):  
Shu-Wen Chen ◽  
Feng Lu ◽  
Yao Ma
Keyword(s):  
Integral Equation ◽  
Fourier Transform ◽  
Fast Fourier Transform ◽  
Green’S Function ◽  
Green's Function ◽  
Electromagnetic Scattering ◽  
Volume Integral ◽  
Scattering Problems ◽  
Volume Integral Equation ◽  
Anisotropic Dielectric

A volume integral equation based fast algorithm using the Fast Fourier Transform of fitting Green’s function (FG-FFT) is proposed in this paper for analysis of electromagnetic scattering from 3D anisotropic dielectric objects. For the anisotropic VIE model, geometric discretization is still implemented by tetrahedron cells and the Schaubert-Wilton-Glisson (SWG) basis functions are also used to represent the electric flux density vectors. Compared with other Fast Fourier Transform based fast methods, using fitting Green’s function technique has higher accuracy and can be applied to a relatively coarse grid, so the Fast Fourier Transform of fitting Green’s function is selected to accelerate anisotropic dielectric model of volume integral equation for solving electromagnetic scattering problems. Besides, the near-field matrix elements in this method are used to construct preconditioner, which has been proved to be effective. At last, several representative numerical experiments proved the validity and efficiency of the proposed method.

Fast modeling of electromagnetic scattering from 2D electrically large PEC objects using the complex line source type Green's function

2019 ◽  
Vol 11 (3) ◽  
pp. 276-286
Author(s):  
Deniz Kutluay ◽  
Taner Oğuzer
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Cross Sections ◽  
Electromagnetic Scattering ◽  
Near Field ◽  
Fixed Number ◽  
Memory Storage ◽  
Position Vector ◽  
Impedance Matrix ◽  
Scattering Problems

AbstractThis study introduces an alternative approach to the numerical solution of two-dimensional (2D) electromagnetic scattering problems by a numerical method of moments (MoM). The real source position vector is replaced by a complex quantity, then Green's function generates a complex source point beam, therefore the interactions between the far zone elements in the impedance matrix are neglected, except the basis functions near to the edges, strongly localizing the impedance matrix. The memory storage increases with the number of edges, but for a fixed number of the edges, it is linearly proportional with N, i.e. O(N). Consequently, the overall running time can be drastically reduced and the far zone scattering pattern and the near field can be found. The proposed procedure is first explained for the single perfectly electrically conducting (PEC) strip geometry, then extended to the scattering by 2D PEC objects with closed polygonal cross-sections. Numerical results are presented for a strip and a square cylinder in both polarizations. The relative errors are also compared with the standard MoM.

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