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F Olyslager - One of the best experts on this subject based on the ideXlab platform.
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series representation of green Dyadics for layered media using pmls
IEEE Transactions on Antennas and Propagation, 2003Co-Authors: F Olyslager, H DerudderAbstract:The Green Dyadics for closed layered media, i.e., layered media bounded by a perfectly conducting plate at the bottom and top of the structure, can be expanded in a discrete surface wave series. For open layered media with semi-infinite layers at the top and/or bottom of the structure, the discrete series needs to be complemented by a branch-cut integral of space waves. In this paper, we present a technique to circumvent this branch-cut integral by truncating the semi-infinite layers with a perfectly matched layer (PML) that is backed by a perfect electric conductor (PEC). It is demonstrated that in this way it is possible to obtain an accurate series or closed-form representation for the Green dyadic of the open layered medium. The series allows a very efficient calculation and storage of the Green dyadic if it is needed for multiple observation and or excitation points. Very close to the source the series loses efficiency. It is shown that the determination of the surface waves in the PML truncated layered medium has the same complexity as the determination of the surface waves in a PEC truncated layered medium without a PML.
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antisymmetric six Dyadics and bi anisotropic media
Journal of Electromagnetic Waves and Applications, 2002Co-Authors: I V Lindell, F OlyslagerAbstract:Novel analytical methods are introduced for antisymmetric six-Dyadics which form a linear space of 15 dimensions. By defining new multiplication operations analogous to those of the classical Gibbsian Dyadics, algebraic handling of equations is greatly simplified. As an application, time-harmonic electromagnetic fields expressed in concise six-vector form are considered. A certain class of bi-anisotropic media, labeled as A media, is defined for which the six-dyadic Maxwell operator can be expressed in terms of an antisymmetric operator. It is shown that, applying six-dyadic identities, the corresponding antisymmetric six-dyadic Green function can be straightforwardly expressed in explicit form.
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factorization and green Dyadics for a new class of bi anisotropic media using duality
Journal of Electromagnetic Waves and Applications, 2000Co-Authors: F Olyslager, I V Lindell, L H PuskaAbstract:In this paper we will study the Green Dyadics and the factorization of the Helmholtz determinant operator for a new class of homogeneous bianisotropic media. That new class of media is derived from previously studied media using a rotational duality transformation. The new class of media is very general and contains many other, previously studied classes, as special cases. The Green Dyadics are expressed in a form that contains a one-dimensional inverse Fourier transformation that, in general, cannot be evaluated in closed form.
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closed form green s Dyadics for a class of media with axial bi anisotropy
IEEE Transactions on Antennas and Propagation, 1998Co-Authors: F Olyslager, I V LindellAbstract:The Green's Dyadics are derived for a new combined nonreciprocal and uniaxial bi-anisotropic medium with material Dyadics of the form /spl mu//sup =//spl alpha//spl epsiv//sup =T/, /spl xi/u/sup =/=/spl xi/u/sub z/u/sub z/, and /spl zeta//sup =/=/spl zeta/u/sub z/u/sub z/. The result can be expressed as an infinite series of exponential integrals. It is investigated for which media this series truncates to a closed-form expression and the result is checked with known Green's Dyadics for special cases of the medium parameters.
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time harmonic two and three dimensional closed form green s Dyadics for gyrotropic bianisotropic and anisotropic media
Electromagnetics, 1997Co-Authors: F OlyslagerAbstract:ABSTRACT The time-harmonic Green‘s Dyadics are studied for homogeneous media consisting of complex bianisotropic media which are characterized by gyrotropic material Dyadics. First the spatial Fourier transform with respect to the preferential axis of these Green‘s Dyadics is calculated in closed form. Then it is shown that it is possible to calculate the inverse transform in closed form when the material parameters satisfy two conditions. These closed form three-dimensional Green‘s Dyadics comprise several known closed form Green‘s Dyadics as special cases.
SaÏd Zouhdi - One of the best experts on this subject based on the ideXlab platform.
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Modified Spherical Wave Functions With Anisotropy Ratio: Application to the Analysis of Scattering by Multilayered Anisotropic Shells
IEEE Transactions on Antennas and Propagation, 2007Co-Authors: SaÏd Zouhdi, Adel RazekAbstract:We describe a novel and rigorous vector eigenfunction expansion of electric-type Green's Dyadics for radially multi- layered uniaxial anisotropic media in terms of the modified spherical vector wave functions, which can take into account the effects of anisotropy ratio systematically. In each layer, the material constitutions e and epsiv macrmu macr are tensors and distribution of sources is arbitrary. Both the unbounded and scattering dyadic Green's functions (DGFs) for rotationally uniaxial anisotropic media are derived in spherical coordinates (r, thetas, phi). The coefficients of scattering DGFs, based on the coupling recursive algorithm satisfied by the coefficient matrix, are derived and expressed in a compact form. With these DGFs obtained, the electromagnetic fields in each layer are straightforward once the current source is known. A specific model is proposed for the scattering and absorption characteristics of multilayered uniaxial anisotropic spheres, and some novel performance regarding anisotropy effects is revealed.
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Modified spherical wave functions with anisotropy ratio: Application of the analysis of scattering by multilayered anisotropic shells
2007Co-Authors: Cheng-wei Qiu, SaÏd Zouhdi, Senior Member, Adel RazekAbstract:Abstract—We describe a novel and rigorous vector eigenfunc-tion expansion of electric-type Green’s Dyadics for radially multi-layered uniaxial anisotropic media in terms of the modified spher-ical vector wave functions, which can take into account the effects of anisotropy ratio systematically. In each layer, the material con-stitutions and are tensors and distribution of sources is arbi-trary. Both the unbounded and scattering dyadic Green’s func-tions (DGFs) for rotationally uniaxial anisotropic media are de-rived in spherical coordinates (). The coefficients of scat-tering DGFs, based on the coupling recursive algorithm satisfied by the coefficient matrix, are derived and expressed in a compact form. With these DGFs obtained, the electromagnetic fields in each layer are straightforward once the current source is known. A spe-cific model is proposed for the scattering and absorption character-istics of multilayered uniaxial anisotropic spheres, and some novel performance regarding anisotropy effects is revealed. Index Terms—Anisotropic ratio, dyadic Green’s functions (DGFs), modified spherical wave functions, radially multilayered structures, recurrence matrix, scattering and absorption, vector eigenfunction expansion. I
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properties of faraday chiral media green Dyadics and negative refraction
Physical Review B, 2006Co-Authors: Hai-ying Yao, Cheng-wei Qiu, SaÏd ZouhdiAbstract:Selected properties of generalized Faraday chiral media are thoroughly studied in this paper where Green’s Dyadics are formulated for unbounded and layered structures, and the possibility of negative refractive index, the backward eigenwaves, and quantum vacuum are also investigated. After a general representation of the Green’s Dyadics is obtained, the scattering coefficients of the Green’s Dyadics are determined from the boundary conditions at each interface and are expressed in a greatly compact form of recurrence matrices. In the formulation of the Green’s Dyadics and their scattering coefficients, three cases are considered, i.e., the current source is immersed in i the intermediate, ii the first, and iii the last regions, respectively. We present here layered dyadic Green’s functions for generalized Faraday chiral media. This kind of Faraday chiral media can also be manipulated to achieve negative refraction and possible backward wave propagation is presented as well. As compared to the existing results, the present work mainly contributes: 1 the exact representation of the dyadic Green’s functions, with irrotational part extracted out, for the gyrotropic Faraday chiral medium in multilayered geometry; 2 the general DGFs and scattering coefficients which can be reduced to either layered chiroferrite, chiroplasma or other simpler cases; and 3 negative refractive index and backward waves achieved with less restriction and more advantages compared to chiral media.
Cheng-wei Qiu - One of the best experts on this subject based on the ideXlab platform.
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Eigenfunctional representation of dyadic Green’s functions in multilayered gyrotropic chiral media
2007Co-Authors: Cheng-wei Qiu, Hai-ying Yao, Tat-soon YeoAbstract:Studying electromagnetic waves in complex media has been an important research topic due to its useful applications and scientific significance of its physical performance. Dyadic Green’s functions (DGFs), as a mathematical kernel or a dielectric medium response, have long been a valuable tool in solving both source-free and source-incorporated electromagnetic boundary value problems for electromagnetic scattering, radiation and propagation phenomena. A complete eigenfunctional expansion of the dyadic Green’s functions for an unbounded and a planar, arbitrary multilayered gyrotropic chiral media is formulated in terms of the vector wavefunctions. After a general representation of Green’s Dyadics is obtained, the scattering coefficients of Green’s Dyadics are determined from the boundary conditions at each interface and are expressed in a greatly compact form of recurrence matrices. In the formulation of Green’s Dyadics and their scattering coefficients, three cases are considered, i.e. the current source is immersed in (1) the first, (2) the intermediate, and (3) the last regions, respectively. Although the dyadic Green’s functions for an unbounded gyroelectric medium has been reported in the literature, we here present not only unbounded but also multilayered DGFs for the gyrotropic chiral media. The explicit representation of the DGFs after reduction to the gyroelectric or isotropic case agrees well with those existing corresponding results. PACS number: 03.50.De 1
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Modified spherical wave functions with anisotropy ratio: Application of the analysis of scattering by multilayered anisotropic shells
2007Co-Authors: Cheng-wei Qiu, SaÏd Zouhdi, Senior Member, Adel RazekAbstract:Abstract—We describe a novel and rigorous vector eigenfunc-tion expansion of electric-type Green’s Dyadics for radially multi-layered uniaxial anisotropic media in terms of the modified spher-ical vector wave functions, which can take into account the effects of anisotropy ratio systematically. In each layer, the material con-stitutions and are tensors and distribution of sources is arbi-trary. Both the unbounded and scattering dyadic Green’s func-tions (DGFs) for rotationally uniaxial anisotropic media are de-rived in spherical coordinates (). The coefficients of scat-tering DGFs, based on the coupling recursive algorithm satisfied by the coefficient matrix, are derived and expressed in a compact form. With these DGFs obtained, the electromagnetic fields in each layer are straightforward once the current source is known. A spe-cific model is proposed for the scattering and absorption character-istics of multilayered uniaxial anisotropic spheres, and some novel performance regarding anisotropy effects is revealed. Index Terms—Anisotropic ratio, dyadic Green’s functions (DGFs), modified spherical wave functions, radially multilayered structures, recurrence matrix, scattering and absorption, vector eigenfunction expansion. I
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properties of faraday chiral media green Dyadics and negative refraction
Physical Review B, 2006Co-Authors: Hai-ying Yao, Cheng-wei Qiu, SaÏd ZouhdiAbstract:Selected properties of generalized Faraday chiral media are thoroughly studied in this paper where Green’s Dyadics are formulated for unbounded and layered structures, and the possibility of negative refractive index, the backward eigenwaves, and quantum vacuum are also investigated. After a general representation of the Green’s Dyadics is obtained, the scattering coefficients of the Green’s Dyadics are determined from the boundary conditions at each interface and are expressed in a greatly compact form of recurrence matrices. In the formulation of the Green’s Dyadics and their scattering coefficients, three cases are considered, i.e., the current source is immersed in i the intermediate, ii the first, and iii the last regions, respectively. We present here layered dyadic Green’s functions for generalized Faraday chiral media. This kind of Faraday chiral media can also be manipulated to achieve negative refraction and possible backward wave propagation is presented as well. As compared to the existing results, the present work mainly contributes: 1 the exact representation of the dyadic Green’s functions, with irrotational part extracted out, for the gyrotropic Faraday chiral medium in multilayered geometry; 2 the general DGFs and scattering coefficients which can be reduced to either layered chiroferrite, chiroplasma or other simpler cases; and 3 negative refractive index and backward waves achieved with less restriction and more advantages compared to chiral media.
Adel Razek - One of the best experts on this subject based on the ideXlab platform.
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Modified Spherical Wave Functions With Anisotropy Ratio: Application to the Analysis of Scattering by Multilayered Anisotropic Shells
IEEE Transactions on Antennas and Propagation, 2007Co-Authors: SaÏd Zouhdi, Adel RazekAbstract:We describe a novel and rigorous vector eigenfunction expansion of electric-type Green's Dyadics for radially multi- layered uniaxial anisotropic media in terms of the modified spherical vector wave functions, which can take into account the effects of anisotropy ratio systematically. In each layer, the material constitutions e and epsiv macrmu macr are tensors and distribution of sources is arbitrary. Both the unbounded and scattering dyadic Green's functions (DGFs) for rotationally uniaxial anisotropic media are derived in spherical coordinates (r, thetas, phi). The coefficients of scattering DGFs, based on the coupling recursive algorithm satisfied by the coefficient matrix, are derived and expressed in a compact form. With these DGFs obtained, the electromagnetic fields in each layer are straightforward once the current source is known. A specific model is proposed for the scattering and absorption characteristics of multilayered uniaxial anisotropic spheres, and some novel performance regarding anisotropy effects is revealed.
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Modified spherical wave functions with anisotropy ratio: Application of the analysis of scattering by multilayered anisotropic shells
2007Co-Authors: Cheng-wei Qiu, SaÏd Zouhdi, Senior Member, Adel RazekAbstract:Abstract—We describe a novel and rigorous vector eigenfunc-tion expansion of electric-type Green’s Dyadics for radially multi-layered uniaxial anisotropic media in terms of the modified spher-ical vector wave functions, which can take into account the effects of anisotropy ratio systematically. In each layer, the material con-stitutions and are tensors and distribution of sources is arbi-trary. Both the unbounded and scattering dyadic Green’s func-tions (DGFs) for rotationally uniaxial anisotropic media are de-rived in spherical coordinates (). The coefficients of scat-tering DGFs, based on the coupling recursive algorithm satisfied by the coefficient matrix, are derived and expressed in a compact form. With these DGFs obtained, the electromagnetic fields in each layer are straightforward once the current source is known. A spe-cific model is proposed for the scattering and absorption character-istics of multilayered uniaxial anisotropic spheres, and some novel performance regarding anisotropy effects is revealed. Index Terms—Anisotropic ratio, dyadic Green’s functions (DGFs), modified spherical wave functions, radially multilayered structures, recurrence matrix, scattering and absorption, vector eigenfunction expansion. I
I V Lindell - One of the best experts on this subject based on the ideXlab platform.
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The Class of Decomposable Media in Four-Dimensional Representation
2020Co-Authors: I V Lindell, L Bergamin, A FavaroAbstract:Abstract The well-known TE/TM decomposition of time-harmonic electromagnetic fields in uniaxial anisotropic media is generalized in terms of four-dimensional differential-form formalism by requiring that the field two-form satisfies an orthogonality condition with respect to two given bivectors. Conditions for the electromagnetic medium in which such a decomposition is possible are derived and found to define three subclasses of media. Two of the subclasses are defined by medium Dyadics which satisfy certain equation of the second order while while the medium dyadic defining the third subclass satisfies an equation of the first order. One of the subclasses is previously known through an analysis applying three-dimensional Gibbsian Dyadics. Dispersion equations for plane waves are derived and the corresponding eigenpolarizations are found for all three subclasses
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special Dyadics and biDyadics
2015Co-Authors: I V LindellAbstract:This chapter considers conditions between Dyadics and biDyadics which may loosely be called orthogonality conditions. It also discusses nilpotent biDyadics, unipotent Dyadics, and projection Dyadics. Projection biDyadics can be studied along similar lines of analysis. Finally, the chapter focuses on modified closure relation for biDyadics.
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CLASS OF BI-QUADRATIC (BQ) ELECTROMAGNETIC MEDIA
2014Co-Authors: I V Lindell, Electromagnetics GroupAbstract:Abstract—Electromagnetic fields and media can be compactly represented by applying the four-dimensional differential-form formalism. In particular, classes of linear (bi-anisotropic) media can be defined in terms of the medium dyadic mapping between the electromagnetic two-forms. As a continuation to the process started by medium Dyadics satisfying linear and quadratic algebraic equations, the class of biquadratic (BQ) media is defined by requiring that the medium Dyadics satisfy the bi-quadratic algebraic equation. It is shown that the corresponding four three-dimensional medium Dyadics are required to satisfy only two dyadic conditions. After studying general properties of BQ media, a special case is analyzed in detail as an example. 1
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antisymmetric six Dyadics and bi anisotropic media
Journal of Electromagnetic Waves and Applications, 2002Co-Authors: I V Lindell, F OlyslagerAbstract:Novel analytical methods are introduced for antisymmetric six-Dyadics which form a linear space of 15 dimensions. By defining new multiplication operations analogous to those of the classical Gibbsian Dyadics, algebraic handling of equations is greatly simplified. As an application, time-harmonic electromagnetic fields expressed in concise six-vector form are considered. A certain class of bi-anisotropic media, labeled as A media, is defined for which the six-dyadic Maxwell operator can be expressed in terms of an antisymmetric operator. It is shown that, applying six-dyadic identities, the corresponding antisymmetric six-dyadic Green function can be straightforwardly expressed in explicit form.
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factorization and green Dyadics for a new class of bi anisotropic media using duality
Journal of Electromagnetic Waves and Applications, 2000Co-Authors: F Olyslager, I V Lindell, L H PuskaAbstract:In this paper we will study the Green Dyadics and the factorization of the Helmholtz determinant operator for a new class of homogeneous bianisotropic media. That new class of media is derived from previously studied media using a rotational duality transformation. The new class of media is very general and contains many other, previously studied classes, as special cases. The Green Dyadics are expressed in a form that contains a one-dimensional inverse Fourier transformation that, in general, cannot be evaluated in closed form.
