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307
Electroseismic waves from point sources in layered media
 J. geophys. Res
, 1997
"... The macroscopic governing equations controlling the coupled electromagnetics and acoustics of porous media are numerically solved for the case of a layered poroelastic medium. It is shown that these coupled equations decouple into two equation sets describing two uncoupled wavefield pictures. That ..."
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Cited by 48 (0 self)
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The macroscopic governing equations controlling the coupled electromagnetics and acoustics of porous media are numerically solved for the case of a layered poroelastic medium. It is shown that these coupled equations decouple into two equation sets describing two uncoupled wavefield pictures. That is, the PSVTM picture where the compressional and vertical polarized mechanical waves drive currents in the P SV particle motion plane that couples to the electromagnetic wavefield components of the T M mode. And the SHTE picture where the horizontal polarized rotational mechanical waves drive currents in the SH particle motion plane that couples to the electromagnetic wavefield components of the T E mode. The global matrix method is employed in computing electroseismograms in layered poroelastic media in the PSVTM picture. The principal features of the converted electromagnetic signals are the following: (1) contacts all antennas at approximately the same time; (2) arrives at the antennas at half of the seismic traveltime at normal incidence reflected P waves; and (3) changes sign on opposite sides of the shot. The seismic pulse is shown to induce electric fields that travel with the compressional wavespeed and magnetic fields that travel with the rotational wavefield. The frequency content of the converted electromagnetic field has the same frequency content of the driving incident seismic pulse, as long as the propagation distances are much less than the electromagnetic skin depth. Snapshots in time and converted electromagnetic amplitudes versus seismic point sourceantenna offsetare calculated for contrasts in mechanical and/or electrical medium property. Conversion happens there where the seismic wavefront passes a contrast in medium properties due to generated imbalances in current across the contrast. The T M component amplitude radiation pattern away from the interface shows similarities with
A study of using metamaterials as antenna substrate to enhance gain”, Prog
 Electromag. Research
, 2005
"... Abstract—Using a commercial software, simulations are done on the radiation of a dipole antenna embedded in metamaterial substrates. Metamaterials under consideration are composed of a periodic collection of rods, or of both rods and rings. The Sparameters of these metamaterials in a waveguide are ..."
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Cited by 33 (1 self)
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Abstract—Using a commercial software, simulations are done on the radiation of a dipole antenna embedded in metamaterial substrates. Metamaterials under consideration are composed of a periodic collection of rods, or of both rods and rings. The Sparameters of these metamaterials in a waveguide are analyzed and compared with their equivalent plasma or resonant structure. Farfield radiation is optimized by analytic method and is simulated numerically. The metamaterial is
Applicationoriented relativistic electrodynamics
 PIER, Progress In Electromagnetics Research
, 1991
"... Abstract–This article is a revised and upgraded edition of a previous one published in this journal, hence the label (2), see the General Remarks section below. Relativistic Electrodynamics, for many years a purely academic subject from the point of view of the applied physicist and electromagnetic ..."
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Cited by 29 (17 self)
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Abstract–This article is a revised and upgraded edition of a previous one published in this journal, hence the label (2), see the General Remarks section below. Relativistic Electrodynamics, for many years a purely academic subject from the point of view of the applied physicist and electromagnetic radiation engineer, is nowadays recognized as pertinent to many practical applications. We therefore need to define a syllabus and explore the best methods for educating future generations of such users. Such an attempt is presented here, and is of course biased by personal preferences. What emerges as general guidelines are the facts that Relativistic Electrodynamics should be presented axiomatically, without trying to “explain the physical meaning ” of Special Relativity, that fourvectors and their mathematical properties should be emphasized, and that the field tensors, an elegant formalism, albeit of limited practical use, should be avoided. Use of fourfold Fourier transforms not only
Magnetodielectrics in electromagnetics: Concept and applications
 IEEE Trans. Anten. Propagat
, 2004
"... Abstract—In this paper, the unique features of periodic magnetodielectric metamaterials in electromagnetics are addressed. These materials, which are arranged in periodic configurations, are applied for the design of novel EM structures with applications in the VHFUHF bands. The utility of theses ..."
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Cited by 29 (1 self)
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Abstract—In this paper, the unique features of periodic magnetodielectric metamaterials in electromagnetics are addressed. These materials, which are arranged in periodic configurations, are applied for the design of novel EM structures with applications in the VHFUHF bands. The utility of theses materials are demonstrated by considering two challenging problems, namely, design of miniaturized electromagnetic bandgap (EBG) structures and antennas in the VHFUHF bands. A woodpile EBG made up of magnetodielectric material is proposed. It is shown that the magnetodielectric woodpile not only exhibits bandgap rejection values much higher than the ordinary dielectric woodpile, but also for the same physical dimensions it shows a rejection band at a much lower frequency. The higher rejection is a result of higher effective impedance contrasts between consecutive layers of the magnetodielectric woodpile structure. Composite magnetodielectrics are also shown to provide certain advantages when used as substrates for planar antennas. These substrates are used to miniaturize antennas while maintaining a relatively high bandwidth and efficiency. An artificial anisotropic metasubstrate having, made up of layered magnetodielectric and dielectric materials is designed to maximize the bandwidth of a miniaturized patch antenna. Analytical and numerical approaches, based on the anisotropic effective medium theory (AEMT) and the finitedifference timedomain (FDTD) technique, are applied to carry out the analyzes and fully characterize the performance of finite and infinite periodic magnetodielectric metamaterials integrated into the EBG and antenna designs. Index Terms—Anisotropic effective medium theory (AEMT), antenna miniaturization, electromagnetic bandgap (EBG) materials, finitedifference timedomain (FDTD) technique, magnetodielectrics, metamaterials, periodic structures. I.
On causality and dynamic stability of perfectly matched layers for FDTD simulations
 IEEE Trans. Microwave Theory Tech
, 1999
"... Abstract—We investigate the spectral properties of the Cartesian, cylindrical, and spherical perfect matched layer (PML) absorbing boundary conditions. In the case of the anisotropicmedium PML formulation, we analyze the analytical properties of the constitutive PML tensors on the complex!plane. In ..."
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Cited by 21 (5 self)
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Abstract—We investigate the spectral properties of the Cartesian, cylindrical, and spherical perfect matched layer (PML) absorbing boundary conditions. In the case of the anisotropicmedium PML formulation, we analyze the analytical properties of the constitutive PML tensors on the complex!plane. In the case of the complexspace PML formulation (complex coordinate stretching formulation), we analyze the analytical properties of field solutions directly. We determine the conditions under which the PML’s satisfy (or do not satisfy) causality requirements in the sense of the realaxis Fourier inversion contour. In the case of the noncausal PML, we point out the implications on the dynamic stability of timedomain equations and finitedifference timedomain (FDTD) simulations. The conclusions have impact both on the design of PML’s for practical FDTD simulations and on the use of PML’s as a physical basis for engineered artificial absorbers on nonplanar (concave or convex) surfaces. Numerical results illustrate the discussion. Index Terms—Absorbing boundary conditions, anisotropic media, dispersive media, FDTD methods, perfectly matched layer. I.
Electromagnetic Theory on a Lattice
 J. Appl. Phys
, 1994
"... In this paper, a selfcontained electromagnetic theory is derived on a regular lattice. The discretized form of integral and differential calculus, which is called `discrete calculus' here, is used to describe this theory. It is shown that discrete forms of Gauss' theorem, Stokes' the ..."
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Cited by 18 (2 self)
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In this paper, a selfcontained electromagnetic theory is derived on a regular lattice. The discretized form of integral and differential calculus, which is called `discrete calculus' here, is used to describe this theory. It is shown that discrete forms of Gauss' theorem, Stokes' theorem, Green's theorem, and Huygens' principle can be derived. Moreover, many electromagnetic theorems can also be derived in this discretized world, for example, reciprocity theorem, uniqueness theorem, and Poynting's theorem. The preservation of these theorems and the conservation of charge imply that the use of this discretized form of Maxwell's equations for numerical simulation will not give rise to spurious solutions due to spurious charges.
Propagation in bianisotropic media—reflection and transmission
 Lund Institute of Technology, Department of
, 1998
"... In this paper a systematic analysis that solves the wave propagation problem in a general bianisotropic, stratified media is presented. The method utilizes the concept of propagators, and the representation of these operators is simplified by introducing the CayleyHamilton theorem. The propagators ..."
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Cited by 18 (11 self)
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In this paper a systematic analysis that solves the wave propagation problem in a general bianisotropic, stratified media is presented. The method utilizes the concept of propagators, and the representation of these operators is simplified by introducing the CayleyHamilton theorem. The propagators propagate the total tangential electric and magnetic fields in the slab and only outside the slab the up/downgoing parts of the fields need to be identified. This procedure makes the physical interpretation of the theory intuitive. The reflection and the transmission dyadics for a general bianisotropic medium with an isotropic (vacuum) half space on both sides of the slab are presented in a coordinateindependent dyadic notation, as well as the reflection dyadic for a bianisotropic slab with perfectly electric backing (PEC). In the latter case the current on the metal backing is also given. Some numerical computations that illustrate the algorithm are presented. 1
Fast inhomogeneous plane wave algorithm for the analysis of electromagnetic scattering
 Radio Sci
"... Abstract—A fast inhomogeneous plane wave algorithm is developed for the electromagnetic scattering problem from the composite bodies of revolution (BOR). PoggioMillerChangHarringtonWu (PMCHW) approach is used for the homogeneous dielectric objects, while the electric field integral equation (EFI ..."
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Cited by 16 (2 self)
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Abstract—A fast inhomogeneous plane wave algorithm is developed for the electromagnetic scattering problem from the composite bodies of revolution (BOR). PoggioMillerChangHarringtonWu (PMCHW) approach is used for the homogeneous dielectric objects, while the electric field integral equation (EFIE) is used for the perfect electric conducting objects. The aggregation and disaggregation factors can be expressed analytically by using the Weyl identity. Compared with the traditional method of moments (MoM), both the memory requirement and CPU time, are reduced for largescale composite BOR problems. Numerical results are given to demonstrate the validity and the efficiency of the proposed method. 1.
Light propagation and scattering in stratified media: A Green’s tensor approach
 J. Opt. Soc. Am. A
, 2001
"... We present a new technique for computing the electromagnetic field that propagates and is scattered in threedimensional structures formed by bodies embedded in a stratified background. This fully vectorial technique is based on the Green’s tensor associated with the stratified background. Its advant ..."
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Cited by 15 (5 self)
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We present a new technique for computing the electromagnetic field that propagates and is scattered in threedimensional structures formed by bodies embedded in a stratified background. This fully vectorial technique is based on the Green’s tensor associated with the stratified background. Its advantage lies in the fact that only the scatterers must be discretized, the stratified background being accounted for in the Green’s tensor. Further, the boundary conditions at the different material interfaces as well as at the edges of the computation window are perfectly and automatically fulfilled. Several examples illustrate the utilization of the technique for the modeling of photonic circuits (integrated optical waveguides), the study of the optics of metal (surface plasmons), and the development of new optical lithography techniques. © 2001 Optical Society of America OCIS codes: 220.3740, 230.0230, 240.0240, 240.6680, 290.0290, 310.0310. 1.