Electromagnetic scattering by a system of two parallel dielectric prolate spheroids

1990 ◽  
Vol 68 (4-5) ◽  
pp. 376-384 ◽  
Author(s):  
M. F. R. Cooray ◽  
I. R. Ciric ◽  
B. P. Sinha
Keyword(s):  
Electromagnetic Wave ◽  
Incident Wave ◽  
Electromagnetic Scattering ◽  
Scattered Field ◽  
Plane Electromagnetic Wave ◽  
Angle Of Incidence ◽  
Algebraic Equations ◽  
Column Matrix ◽  
Prolate Spheroids ◽  
Expansion Coefficients

An exact solution to the problem of scattering of a plane electromagnetic wave by two dielectric prolate spheroids with parallel major axes is obtained by expanding the incident, scattered, and transmitted electric and magnetic fields in terms of an appropriate set of vector spheroidal eigenfunctions. The incident wave is considered to be a monochromatic, uniform plane electromagnetic wave of arbitrary polarization and angle of incidence. The boundary conditions are imposed by expressing the electromagnetic field scattered by one spheroid in terms of the spheroidal coordinates attached to the other, using the translational addition theorems for vector spheroidal wave functions. The column matrix of the total transmitted and scattered field-expansion coefficients is equal to the product of a square matrix, which is independent of the direction and polarization of the incident wave, and the column matrix of the known incident field-expansion coefficients. The solution of the associated set of algebraic equations gives the unknown transmitted and scattered field-expansion coefficients. Even though the problem is formulated in general, the numerical results are presented for the bistatic and backscattering cross sections of two lossless prolate spheroids with various axial ratios and center-to-center distances.

scholarly journals OPERATOR METHOD IN THE PROBLEM OF A PLANE ELECTROMAGNETIC WAVE DIFFRACTION BY AN ANNULAR SLOT IN THE PLANE OR BY A RING

2021 ◽  
Vol 26 (4) ◽  
pp. 350-357
Author(s):  
M. E. Kaliberda ◽  
◽  
L. M. Lytvynenko ◽  
S. A. Pogarsky ◽  
◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Circular Hole ◽  
Wave Diffraction ◽  
Scattered Field ◽  
Plane Electromagnetic Wave ◽  
Operator Method ◽  
Fredholm Integral Equations ◽  
Fourier Amplitude ◽  
Annular Slot ◽  
Electromagnetic Wave Diffraction

Purpose: The problem of a plane electromagnetic wave diffraction by an annular slot in the perfectly conducting zero thickness plane is considered. As a dual problem, the problem of diffraction by a perfectly conducting zero thickness ring is also considered. The paper aims at developing the operator method for the axially symmetric structures placed in free space. Design/methodology/approach: The problem is considered in the spectral domain. The scattered field is expressed in terms of unknown Fourier amplitudes (spectral functions). The annular slot is given as a unity of two simple discontinuities, namely of a disk and a circular hole in the plane, which interact with each other. The Fourier amplitude of the scattered field is sought as a sum of two amplitudes, the Fourier amplitude of the field of currents on the disk and Fourier amplitude of the field of currents on the perfectly conducting plane with circular hole. The operator equations are written for these amplitudes, which take into account the electromagnetic coupling of the disk and the hole in the plane. The equations use the reflection operators of a single isolated disk and a single hole in the plane. They are supposed to be known and can be obtained for example by the method of moments.The reflection operators can have singularities. After transformations, the equations are obtained, which are equivalent to the Fredholm integral equations of second kind and they can be solved numerically. Findings: The operator equations relative to the Fourier amplitudes of the field scattered by the discussed structure are obtained. The far zone scattered field for an annular slot and a ring for different values of parameters are studied. Conclusions: The rigorous solution of the problem of the electromagnetic wave diffraction by an annular slot in the plane and by a circular ring is obtained. The problem is reduced to the Fredholm integral equations of second kind. The far field distribution for different parameters is studied. The developed approach is an effective instrument for a number of problems of antenna technique to be solved. Key words: circular hole; disk; annular slot; ring; operator method; diffraction

DIFFRACTION BY A CONDUCTING HALF-PLANE IN AN ANISOTROPIC PLASMA

1964 ◽  
Vol 42 (8) ◽  
pp. 1455-1468 ◽  
Author(s):  
E. V. Jull
Keyword(s):  
Magnetic Field ◽  
Half Plane ◽  
Scattered Field ◽  
Plane Electromagnetic Wave ◽  
Plane Waves ◽  
Angular Spectrum ◽  
Anisotropic Plasma ◽  
Angle Of Incidence ◽  
Dual Integral Equations ◽  
Magnetostatic Field

The diffraction of a plane electromagnetic wave by a perfectly conducting half-plane in an anisotropic plasma is considered. The plasma is characterized by a permittivity tensor and the wave is assumed to propagate in a direction normal to the magnetostatic field and the diffracting edge, but its angle of incidence is otherwise arbitrary. Only the H-polarized wave of the incident field, which has a single magnetic field component parallel to the edge, is affected by the anisotropy and the analysis is restricted accordingly. Representing the scattered field as an angular spectrum of plane waves leads to dual integral equations from which an expression for the scattered field is obtained. The total field is then reduced to Fresnel integrals and its far-field behavior is investigated. Agreement with Seshadri and Rajagopal's result for a wave normally incident on the conductor, which was obtained by using the Wiener–Hopf technique, is found. The differences between isotropic and anisotropic solutions to this problem, which arise from the differing boundary conditions on the tangential magnetic field, are examined.

scholarly journals A Generalized case of Electromagnetic Scattering from a finite number of Ferromagnetic cylinders

2015 ◽  
Vol 4 (3) ◽  
pp. 8 ◽  
Author(s):  
T. Kumar ◽  
N. Kalyanasundaram ◽  
B. K. Lande
Keyword(s):  
Finite Number ◽  
Electromagnetic Scattering ◽  
Scattered Field ◽  
Near Field ◽  
Scattering Problem ◽  
Normal Incidence ◽  
Generalized Solution ◽  
Numerical Results ◽  
Infinite Length ◽  
Angle Of Incidence

A generalized solution of the scattering problem from an array containing a finite number of axially magnetized ferromagnetic cylinders of infinite length placed in free space is presented in this paper. The analysis is carried out by matching the tangential boundary conditions at the surface of each cylinder to find the unknown expansion coefficients of the scattered field. Planar arrays consist of a finite number of ferromagnetic microwires are considered to obtain the numerical results for TMz and TEz polarizations in terms of the variation in scattered field components of the near field and scattering cross section (SCS) with respect to angle of incidence, radius of microwires, spacing among the microwires and operating frequency. For validation purpose, numerical results of the proposed analysis specialized for the case of single microwire and normal incidence for TMz polarization are compared with the results available in the literature for the specialized case and both are found to be matched completely.

scholarly journals Intensity of Electromagnetic Wave into Layers with Fluctuations of Dielectric Permittivity

2021 ◽  
Vol 13 (1) ◽  
pp. 3-12
Author(s):  
Gennady I. Grigor’ev ◽  
◽  
Tatiana M. Zaboronkova ◽  
Lev P. Kogan ◽  
◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Dielectric Permittivity ◽  
Scattered Field ◽  
Plane Electromagnetic Wave ◽  
Average Intensity ◽  
Average Amplitude ◽  
Rectangular Shape ◽  
Mean Intensity ◽  
Triangular Profile ◽  
The Mean

The study is made of the intensity of a plane electromagnetic wave propagating into the layer with random discrete irregularities of the dielectric permittivity. The mean intensity of scattered field as a function of the parameters of random irregularities of rectangular and triangular forms is analyzed. It is shown that the deviation of the average intensity from the unperturbed value increases both the average amplitude and its standard of fluctuations. It is found that the amplitude of the intensity oscillations for a layer with irregularities of the rectangular shape is significantly greater than for fluctuations with the triangular profile.

Electromagnetic scattering by a dielectric sphere partially buriedin an infinte plane

2002 ◽  
Vol 80 (9) ◽  
pp. 979-986
Author(s):  
A -K Hamid ◽  
M Hamid
Keyword(s):  
Plane Wave ◽  
Electromagnetic Scattering ◽  
Plane Electromagnetic Wave ◽  
Ground Plane ◽  
Scattering Problem ◽  
Dielectric Constants ◽  
Angle Of Incidence ◽  
Spherical Scatterer ◽  
Incident Plane ◽  
The Given

An analytical solution of the scattering problem of a plane electromagnetic wave scattered by a dielectric spherical scatterer residing or partially buried in an infinite perfectly conducting ground plane is formulated in conjunction with the method of images. With imaging, the geometry is replaced by two touching or overlapping dielectric spheres in the absence of the ground plane, but with the given incident plane wave and its plane-wave image to satisfy the boundary conditions on the ground plane in the original problem. Numerical results are presented for the normalized scattering cross section at an arbitrary height from the ground plane, at any specific angle of incidence, and different relative dielectric constants. PACS Nos.: 41.10H, 41.90

DIFFRACTION OF A PLANE ELECTROMAGNETIC WAVE BY AN INFINITE SET OF PARALLEL METALLIC PLATES IN AN ANISOTROPIC PLASMA

1967 ◽  
Vol 45 (5) ◽  
pp. 1911-1923 ◽  
Author(s):  
C. P. Wu
Keyword(s):  
Electromagnetic Wave ◽  
Plane Electromagnetic Wave ◽  
Angle Of Incidence ◽  
Parallel Plates ◽  
Rapid Variation ◽  
Magnetostatic Field ◽  
Transmission Coefficients ◽  
Phase Functions ◽  
Infinite Set ◽  
Metallic Plates

The diffraction of a plane electromagnetic wave by an infinite set of parallel metallic plates is considered. The plates are assumed to be vanishingly thin and infinitely conducting, and are immersed in a cold plasma which is rendered anisotropic by an external magnetostatic field parallel to the edges of the plates. An exact solution is obtained by using the Wiener–Hopf technique for the case in which the fields have no variation in the direction of the external static magnetic field.It is found that, because of the anisotropy of the medium, the reflection becomes nonvanishing for the TM mode incident normally at the interface between the parallel plates and the free plasma regions. Also, the reflection coefficient is no longer an even or odd function of the angle of incidence. When the degree of anisotropy is relatively small, the results practically reduce to those in an isotropic dielectric, except that the phase functions of the reflection and transmission coefficients would experience a rapid variation for small incident angles. Some numerical examples showing the effects of anisotropy are given.

scholarly journals HIGH-FREQUENCY SCATTERING FROM A COATED CYLINDER

1964 ◽  
Vol 42 (11) ◽  
pp. 2121-2128 ◽  
Author(s):  
P. L. E. Uslenghi
Keyword(s):  
Electromagnetic Wave ◽  
Scattered Field ◽  
High Frequency ◽  
Plane Electromagnetic Wave ◽  
Normal Incidence ◽  
Index Of Refraction ◽  
Wave Incident ◽  
Complex Index ◽  
Coated Cylinder ◽  
Complex Index Of Refraction

The scattered field produced by a plane electromagnetic wave incident on an infinitely long imperfectly conducting cylinder coated with a layer of material with complex index of refraction is considered. The geometric optics and the creeping wave contributions to the backscattered field are obtained, for normal incidence and small wavelengths.

Electromagnetic scattering by a lossy dielectric-coated elliptic cylinder

2003 ◽  
Vol 81 (5) ◽  
pp. 771-778 ◽  
Author(s):  
A -K Hamid ◽  
M I Hussein
Keyword(s):  
Electromagnetic Wave ◽  
Electromagnetic Scattering ◽  
Scattered Field ◽  
Wave Scattering ◽  
Elliptic Cylinder ◽  
Numerical Results ◽  
Dielectric Constants ◽  
Mathieu Functions ◽  
Electromagnetic Wave Scattering ◽  
Lossy Dielectric

The problem of electromagnetic wave scattering by a lossy dielectric-coated elliptic cylinder is analyzed using elliptic waves expressed in terms of complex Mathieu functions. Numerical results are obtained for the scattered field in the far zone for different axial ratios, lossy dielectric constants, and angles of incidence. The numerical results show a significant change in backscattering echo due to the lossy dielectric coating. PACS No.: 42.25.Fx

On the Inverse Problem of Scattering from a Perfectly Conducting Elliptic Cylinder

1972 ◽  
Vol 50 (17) ◽  
pp. 1987-1992 ◽  
Author(s):  
F. H. Vandenberghe ◽  
W. M. Boerner
Keyword(s):  
Inverse Problem ◽  
Electromagnetic Scattering ◽  
Scattered Field ◽  
Low Frequency ◽  
Elliptic Cylinder ◽  
Cylindrical Wave ◽  
Wave Functions ◽  
Principal Axes ◽  
Expansion Coefficients ◽  
Model Technique

The inverse problem of electromagnetic scattering from a perfectly conducting elliptic cylinder for the low-frequency case is considered. The approach is based on the model technique presented in Boerner and Vandenberghe, conjecturing that the salient features of the scatterer can be determined from the far scattered field via matrix inversion. This follows the low-frequency formulation of the scattered field as given by Udagawa and Miyazaki rather than from an expansion in the elliptic cylindrical wave functions. It is then shown that the characteristic parameters of the ellipse, i.e. the principal axes a′ and b′ and the numerical eccentricity ε, can be directly recovered from the expansion coefficients associated with circular cylindrical wave functions, as is presented in Udagawa and Miyazaki.

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