| 1. |
- Karlsson, Anders, et al.
(författare)
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Transient wave propagation in gyrotropic media
- 1992
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Ingår i: Invariant inbedding and inverse problems. - 0898713056 ; , s. 77-89
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- In this paper transient electromagnetic wave propagation in an inhomogeneous, cold plasma is considered. It is assumed that a constant magnetic induction is present and that the plasma is spatially inhomogeneous in the direction of the magnetic induction. Losses in the plasma are modeled with a collision frequency ν. The direct problem, which is to calculate the reflected and transmitted responses of the plasma, is considered in this paper. Special attention is paid to the precursor effects in the plasma and several examples of precursor effects in an inhomogeneous plasma are showed.
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| 2. |
- Karlsson, Anders, et al.
(författare)
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Wave splitting and imbedding equations for a spherically symmetric dispersive medium
- 1992
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Ingår i: Invariant inbedding and inverse problems. - 0898713056 ; , s. 103-113
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The direct problem of time dependent electromagnetic scattering in the dispersive sphere is solved by a wave splitting technique. The electric field is expanded in a series involving vector spherical harmonics, leading to a system of wave equations for each term. These systems are reduced to scalar wave equations for each term, which are solved via reflection operators. Some preliminary numerical results are presented.
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| 3. |
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| 4. |
- Bernekorn, Peter, et al.
(författare)
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Propagation of transient electromagnetic waves in inhomogeneous and dispersive waveguides
- 1995
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Transient wave propagation in a waveguide filled with an inhomogeneous dispersive medium is analyzed. The waveguide is inhomogeneous in the longitudinal direction, but is homogeneously filled in the transverse directions. The analysis is performed in the time domain and is based upon a wave splitting technique and the method of propagators. The propagator maps the exciting field from one position in the waveguide to the field at another position. This mapping is represented as time convolution integrals. The theory is exemplified by numerical examples where it is shown how wave trains of different shapes are propagating in a waveguide filled with a homogeneous dispersive medium.
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| 5. |
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| 6. |
- Gustafsson, Mats, et al.
(författare)
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A time-domain approach to the extinction paradox for scattering of electromagnetic waves
- 2008
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Ingår i: ; , s. 1-4
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Konferensbidrag (refereegranskat)abstract
- The extinction paradox states that a perfectly electric conducting target which is large compared to the wavelength removes from the incident radiation exactly twice the amount of power it can intercept by its geometrical cross section area. In this paper, the extinction paradox is generalized to include temporally dispersive material parameters with finite values of the permittivity and the permeability. From a time-domain approach it is shown that the high-frequency limit of the extinction cross section depends on the material parameters of the target and that a limiting value not necessarily exists. These findings are exemplified by several numerical illustrations with different values of the extinction cross section in the high-frequency limit.
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| 7. |
- Karlsson, Anders, et al.
(författare)
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Constitutive relations, dissipation and reciprocity for the Maxwell equations in the time domain
- 1992
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Ingår i: Journal Electromagnetic Waves and Applications. - 1569-3937. ; 6:5-6, s. 537-551
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Tidskriftsartikel (refereegranskat)abstract
- The main goal of this paper is to establish general constitutive relations for the electromagnetic fields EBAR, DBAR, BBAR, and HBAR in a time domain setting. The four basic assumptions of the medium are linearity, invariance to time translations, causality, and continuity. These four assumptions imply that the constitutive relations are convolutions of the Riemann-Stieltjes type. A review of the classification of media in bianisotropic, biisotropic, anisotropic, and isotropic media, respectively, is made. Dissipation and reciprocity are defined and the constraints these concepts make on the constitutive relations are analyzed. Furthermore, an appropriate form of time reversal and functions of positive type are introduced and some consequences of these concepts are showed.
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| 8. |
- Karlsson, Anders, et al.
(författare)
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Constitutive relations, dissipation and reciprocity for the Maxwell equations in the time domain
- 1989
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The main goal of this paper is to establish general constitutive relations for the electromagnetic fields E,D,B and H in a time domain setting. The four basic assumptions of the medium are linearity, invariance to time translations, causality and continuity. These four assumptions imply that the constitutive relations are convolutions of Riemann-Stieltjes type. A review of the classifi- cation of media in bianisotropic, biisotropic, anisotropic and isotropic media, respectively, is made. Dissipation and reciprocity are defined and the constraints these concepts make on the constitutive relations are analyzed in detail. Furthermore, an appropriate form of time reversal and functions of positive type are introduced and some consequences of these concepts are showed.
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| 9. |
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| 10. |
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