Electromagnetic scattering by cylindrical orthotropic waveguide irises

2011 ◽  
Vol 18 (1) ◽  
pp. 99-120
Author(s):  
Luis P. Castro ◽  
Roland Duduchava ◽  
David Kapanadze
Keyword(s):  
Electromagnetic Scattering ◽  
Electromagnetic Waves ◽  
Symmetric Matrix ◽  
Plane Waves ◽  
Regularity Of Solutions ◽  
Bessel Potential ◽  
Time Harmonic ◽  
Dimensional Boundary ◽  
Definite Symmetric Matrix ◽  
Boundary Contact

Abstract The paper is devoted to the mathematical analysis of scattered time-harmonic electromagnetic waves by an infinitely long cylindrical orthotropic waveguide iris. This is modeled by an orthotropic Maxwell system in a cylindrical waveguide iris for plane waves propagating in the x 3-direction, imbedded in an isotropic infinite medium. The problem is equivalently reduced to a 2-dimensional boundary-contact problem with the operator div M grad+k 2 inside the domain and the (Helmholtz) operator Δ+k 2 = div grad+k 2 outside the domain. Here M is a 2 × 2 positive definite, symmetric matrix with constant, real valued entries. The unique solvability of the appropriate boundary value problems is proved and the regularity of solutions is established in Bessel potential spaces.

scholarly journals Analysis Method for the Heating of the Human Eye Exposed to High Frequency Electromagnetic Fields

2007 ◽  
Vol 3 (1) ◽  
pp. 3 ◽  
Author(s):  
Andrés Peratta ◽  
Dragan Poljak
Keyword(s):  
Electromagnetic Scattering ◽  
High Frequency ◽  
Electromagnetic Waves ◽  
Specific Absorption Rate ◽  
Scattering Problem ◽  
Analysis Method ◽  
Human Eye ◽  
Time Harmonic ◽  
Standard Finite Element Method ◽  
Frequency Radiation

The paper studies the thermal rise in the human eye caused by time harmonic electromagnetic waves. An eye has been illuminated by a high frequency plane wave with powerdensity 5.0 mW/cm2. Such a problem has been considered as an electromagnetic scattering problem since part of EM energy is transmitted to the eye and part of it is reflected. The total electric field inside an eye and related Specific Absorption Rate (SAR) has been calculated in a frequency range from 0.7 to 4.4 GHz via a hybrid BEM/FEM approach. Knowing the SAR distribution inside the eye provides the calculation of related temperature rise in the human eye due to high frequency radiation by solving Bio-Heat Transfer Equation via standard finite element method.

Multiple scattering of electromagnetic waves by finitely many point-like obstacles

2014 ◽  
Vol 24 (05) ◽  
pp. 863-899 ◽  
Author(s):  
Durga Prasad Challa ◽  
Guanghui Hu ◽  
Mourad Sini
Keyword(s):  
Multiple Scattering ◽  
Electromagnetic Scattering ◽  
Electromagnetic Waves ◽  
Plane Waves ◽  
Field Measurements ◽  
Scattered Wave ◽  
Three Dimensions ◽  
Music Algorithm ◽  
Scattering Problems ◽  
Scattering Coefficients

This paper is concerned with the direct and inverse time-harmonic electromagnetic scattering problems for a finite number of isotropic point-like obstacles in three dimensions. In the first part, we show that the representation of scattered fields obtained using the Foldy physical assumption "on the proportionality of the strength of the scattered wave on a given scatterer to the external field on it" is the same as the one derived from the model corresponding to the scattering by Dirac-like refraction indices. Using the regularization approach known in quantum mechanics, we rigorously deduce the solution operator (Green's tensor) of the last model in appropriate weighted spaces. Intermediate levels of the scattering between the Born and Foldy models are also described. In the second part, we apply the MUSIC algorithm to the inverse problem of detecting both the position of point-like scatterers and the scattering coefficients attached to them from the far-field measurements of finitely many incident plane waves, with an emphasis on discussing the effect of multiple scattering.

scholarly journals A UNIQUENESS THEOREM FOR AN INVERSE ELECTROMAGNETIC SCATTERING PROBLEM IN INHOMOGENEOUS ANISOTROPIC MEDIA

2003 ◽  
Vol 46 (2) ◽  
pp. 293-314 ◽  
Author(s):  
Fioralba Cakoni ◽  
David Colton
Keyword(s):  
Anisotropic Medium ◽  
Electromagnetic Scattering ◽  
Maxwell’S Equations ◽  
Maxwell's Equations ◽  
Scattering Problem ◽  
Plane Waves ◽  
Field Patterns ◽  
Regularity Properties ◽  
Time Harmonic ◽  
Secondary 35P25

AbstractWe show that the support of a (possibly) coated anisotropic medium is uniquely determined by the electric far-field patterns corresponding to incident time-harmonic electromagnetic plane waves with arbitrary polarization and direction. Our proof avoids the use of a fundamental solution to Maxwell’s equations in an anisotropic medium and instead relies on the well-posedness and regularity properties of solutions to an interior transmission problem for Maxwell’s equations.AMS 2000 Mathematics subject classification: Primary 35R30; 35Q60. Secondary 35P25; 78A45

Electromagnetic waves

2018 ◽  
Author(s):  
Nathalie Deruelle ◽  
Jean-Philippe Uzan
Keyword(s):  
Plane Wave ◽  
Electromagnetic Waves ◽  
Maxwell Equations ◽  
Plane Waves ◽  
Geometrical Optics ◽  
Particle Detection ◽  
Spatial Coordinates ◽  
A Charge

This chapter examines solutions to the Maxwell equations in a vacuum: monochromatic plane waves and their polarizations, plane waves, and the motion of a charge in the field of a wave (which is the principle upon which particle detection is based). A plane wave is a solution of the vacuum Maxwell equations which depends on only one of the Cartesian spatial coordinates. The monochromatic plane waves form a basis (in the sense of distributions, because they are not square-integrable) in which any solution of the vacuum Maxwell equations can be expanded. The chapter concludes by giving the conditions for the geometrical optics limit. It also establishes the connection between electromagnetic waves and the kinematic description of light discussed in Book 1.

STRONG AND WEAK FORMS OF THE METHOD OF MOMENTS AND THE COUPLED DIPOLE METHOD FOR SCATTERING OF TIME-HARMONIC ELECTROMAGNETIC FIELDS

1992 ◽  
Vol 03 (03) ◽  
pp. 583-603 ◽  
Author(s):  
AKHLESH LAKHTAKIA
Keyword(s):  
Electromagnetic Fields ◽  
Method Of Moments ◽  
Electromagnetic Scattering ◽  
Final Section ◽  
The Other ◽  
Numerical Techniques ◽  
Scattering Problems ◽  
Time Harmonic

Algorithms based on the method of moments (MOM) and the coupled dipole method (CDM) are commonly used to solve electromagnetic scattering problems. In this paper, the strong and the weak forms of both numerical techniques are derived for bianisotropic scatterers. The two techniques are shown to be fully equivalent to each other, thereby defusing claims of superiority often made for the charms of one technique over the other. In the final section, reductions of the algorithms for isotropic dielectric scatterers are explicitly given.

Scattering of a Plane Elastic Wave From Objects Near an Interface

1972 ◽  
Vol 39 (4) ◽  
pp. 1019-1026 ◽  
Author(s):  
Stephen B. Bennett
Keyword(s):  
Elastic Wave ◽  
Electromagnetic Waves ◽  
Three Dimensions ◽  
Circular Cylinders ◽  
Scattering Problems ◽  
Reflection And Refraction ◽  
Time Harmonic ◽  
Incident Plane ◽  
Boundary Curves ◽  
Consistent Formulation

The displacement field generated by the reflection and refraction of plane (time harmonic) elastic waves by finite obstacles of arbitrary shape, in the neighborhood of a plane interface between two elastic media, is investigated. The technique employed allows a consistent formulation of the problem for both two and three dimensions, and is not limited either to boundary shapes which are level surfaces in appropriate coordinate systems, i.e., circular cylinders, spheres, etc., or to closed boundary curves or surfaces. The approach is due to Twersky, and has been applied to many problems of the scattering of electromagnetic waves. The method consists of expressing the net field due to all multiple scattering in terms of the field reflected from each boundary in isolation when subjected to an incident plane elastic wave. Thus the technique makes use of more elemental scattering problems whose solutions are extant. By way of illustration, a numerical solution to the scattering of a plane elastic wave by a rigid circular cylindrical obstacle adjacent to a plane free surface is considered.

Improved algorithm for electromagnetic scattering of plane waves and shaped beams by multilayered spheres

1997 ◽  
Vol 36 (21) ◽  
pp. 5188 ◽  
Author(s):  
Zhen Sen Wu ◽  
Li Xin Guo ◽  
Kuan Fang Ren ◽  
Gérard Gouesbet ◽  
Gérard Gréhan
Keyword(s):  
Electromagnetic Scattering ◽  
Plane Waves ◽  
Improved Algorithm
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