An efficient high-frequency method of the EM near-field scattering from an electrically large target

Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Conghui Qi ◽  
Yang Yi ◽  
Wei Yang
Keyword(s):  
High Frequency ◽  
Near Field ◽  
Scattering Problem ◽  
Physical Optics ◽  
Field Calculation ◽  
Frequency Method ◽  
Scattering Problems ◽  
Large Target ◽  
Expansion Technique ◽  
Near Zone

Abstract In this paper, an efficient high-frequency method combining physical optics and shooting and bouncing rays is proposed to calculate the electromagnetic near-field scattering from the electrically large target (such as ship) in the near zone. In order to solve the mono-static and bi-static scattering problems, the local expansion technique based on the facets of target is presented to account for the near-field scattering, which has a singularity-free characteristic. And then the near-field contour-integral representation is introduced by refining the formulations in traditional far-field calculation to reduce the computational complexity. Therefore, this method is more straightforward to deal with the near-field scattering problem. Finally, some analyses on the near-field scattering characteristics and Doppler spectra of a surveillance ship in near zone are investigated by using the proposed method.

scholarly journals Imaging of bi-anisotropic periodic structures from electromagnetic near-field data

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Dinh-Liem Nguyen ◽  
Trung Truong
Keyword(s):  
Inverse Scattering ◽  
Maxwell Equations ◽  
Field Data ◽  
Periodic Structures ◽  
Near Field ◽  
Scattering Problem ◽  
Three Dimensional ◽  
Inverse Scattering Problem ◽  
Factorization Method ◽  
Unique Determination

AbstractThis paper is concerned with the inverse scattering problem for the three-dimensional Maxwell equations in bi-anisotropic periodic structures. The inverse scattering problem aims to determine the shape of bi-anisotropic periodic scatterers from electromagnetic near-field data at a fixed frequency. The factorization method is studied as an analytical and numerical tool for solving the inverse problem. We provide a rigorous justification of the factorization method which results in the unique determination and a fast imaging algorithm for the periodic scatterer. Numerical examples for imaging three-dimensional periodic structures are presented to examine the efficiency of the method.

Algorithms for solving scattering problems for the Manakov model of nonlinear Schrödinger equations

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Leonid L. Frumin
Keyword(s):  
Scattering Problem ◽  
Inverse Scattering Problem ◽  
Numerical Algorithms ◽  
Scattering Problems ◽  
Block Matrices ◽  
Nonlinear Schrödinger ◽  
Direct Scattering ◽  
Vector Case ◽  
Manakov Model ◽  
Vector Variant

AbstractWe introduce numerical algorithms for solving the inverse and direct scattering problems for the Manakov model of vector nonlinear Schrödinger equation. We have found an algebraic group of 4-block matrices with off-diagonal blocks consisting of special vector-like matrices for generalizing the scalar problem’s efficient numerical algorithms to the vector case. The inversion of block matrices of the discretized system of Gelfand–Levitan–Marchenko integral equations solves the inverse scattering problem using the vector variant the Toeplitz Inner Bordering algorithm of Levinson’s type. The reversal of steps of the inverse problem algorithm gives the solution of the direct scattering problem. Numerical tests confirm the proposed vector algorithms’ efficiency and stability. We also present an example of the algorithms’ application to simulate the Manakov vector solitons’ collision.

scholarly journals Measurement of high frequency conductivity of oxide-doped anti-ferromagnetic thin film with a near-field scanning microwave microscope

AIP Advances ◽  
2014 ◽  
Vol 4 (4) ◽  
pp. 047114 ◽  
Author(s):  
Z. Wu ◽  
A. D. Souza ◽  
B. Peng ◽  
W. Q. Sun ◽  
S. Y. Xu ◽  
...  
Keyword(s):  
Thin Film ◽  
High Frequency ◽  
Near Field ◽  
Microwave Microscope ◽  
Near Field Scanning
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