Diffraction of the Pulsed Field from an Arbitrarily Oriented Electric or Magnetic Dipole by a Perfectly Conducting Wedge

Felsen, L. B.

doi:10.1137/0126028

Cited by 31 publications

(13 citation statements)

References 3 publications

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“…In the soft and hard cases (TM and TE polarization, respectively, for the perfectly conducting wedge), the poles are integers or half integers and the summations are elementary. These are the Biot-Tolstoy solutions [2] that were rederived by Felsen [4], and further details are given in [1] in the verification of this limiting case of no penetration. In general, the poles are the roots of transcendental equations and the corresponding residues appear to defy summation.…”

Section: Transform Analysis For the Isorefractive Wedgementioning

confidence: 99%

“…The Hertzian electric dipole of Fig. 1 is represented by the volume density of electric current (4) Continuity of charge requires the accompanying volume density of electric charge (5) which is an electrostatic dipole created by the impulsive current at time . Symmetry about the wedge bisector allows the source angle to be restricted to the range .…”

Section: A Hertzian Electric Dipolementioning

confidence: 99%

“…The Biot-Tolstoy exact solution to the canonical soft/hard wedge diffraction is often cited in the acoustics literature and is the basic building block of a time domain analog of geometrical theory of diffraction (GTD) modeling called the "wedge assemblage method" [3]. The application of the Biot and Tolstoy ideas to the TM/TE electromagnetic scattering by the perfectly conducting wedge was presented by Felsen [4] and is mentioned in the Soviet translation [5]. However, our electromagnetics community has apparently ignored this interesting time domain solution in favor of, for example, numerical Fourier transformation of the time-harmonic GTD results [6].…”

Section: Introductionmentioning

confidence: 99%

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Time-domain three-dimensional diffraction by the isorefractive wedge

Scharstein

Davis

1998

IEEE Trans. Antennas Propagat.

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The extension of the Biot-Tolstoy exact time domain solution to the electromagnetic isovelocity or isorefractive wedge is described. The TM field generated by a Hertzian electric dipole can be represented by a vector potential parallel to the apex of the wedge and a scalar potential necessitated by the three dimensionality of the magnetic field. The derivation of the former is exactly that of the pressure in the corresponding acoustic situation [1], and a more efficient version of the lengthy details is presented herein. A Lorentz gauge determines the scalar potential from the vector potential, and the diffracted field contains impulsive and "switch-on" terms that cannot be evaluated in closed form. The ratio of arrival times, at a given point, of the geometrical optics and diffracted fields provides a convenient parameter, in addition to the usual metric-related variable, for graphically displaying this scalar potential.

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Section: Transform Analysis For the Isorefractive Wedgementioning

confidence: 99%

Section: A Hertzian Electric Dipolementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Time-domain three-dimensional diffraction by the isorefractive wedge

Scharstein

Davis

1998

IEEE Trans. Antennas Propagat.

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“…Therefore, the condition of integrability following the transform pair of (11) and (12) is not satisfied, and the Mellin inversion formula cannot be directly applied to the functions in (27)- (29). Mathematically, operating with the 4-derivative of the potential temporarily removes this troublesome logarithmic variation, which is then restored following the convergent Mellin inversion.…”

Section: E Inverse Mellin Transform For the Case Of Even Symmetrymentioning

confidence: 99%

Acoustic or Electromagnetic Scattering from the Penetrable Wedge

Scarstein¹

1993

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Puic rwartlt WMI"n 1w Oftls €of~tao dl Iniamobn is emkaiml to &map I hourn pw teslWne, in; hen incof. seaaching eziuig data soecee. Abstract (Maximum 200 words).The intentional *or" in the title of this report emphasizes the exact, mathematical equivalence between the acoustic and electromagnetic scattering problems for a two-dimensional, penetrable wedge. A z-directed, time-harmonic line source at the transverse (xy) position r is external and parallel to the wedge of an infinite wedge of included angle 2a. Both the exterior (region 1) and interior (region 2) are composed of simple media having linear, isotropic, and homogeneous properties. The College of Engineering at The University of Alabama has an undergraduate enrollment of 1,800 students and a graduate enrollment exceeding 250. There are approximately 100 faculty members, a significant number of whom conduct research in addition to teaching.Research is an integral part of the educational program, and research interests of the faculty parallel academic specialities. A wide variety of projects are included in the overall research effort of the College, and these projects form a solid base for the graduate program which offers fourteen different master's and five different doctor of philosophy degrees.Other This University community provides opportunities for interdisciplinary work in pursuit of the basic goals of teaching, research, and public service. BUREAU OF ENGINEERING RESEARCHThe Bureau of Engineering Research (BER) is an integral part of the College of Engineering of The University of Alabama. The primary functions of the BER Include: 1) identifying sources of funds and other outside support bases to encourage and promote the research and educational activities within the College of Engineering; 2) organizing and promoting the research interests and accomplishments of the engineering faculty and students; 3) assisting in the preparation coordination, and execution of proposals, including research, equipment, and instructional proposals; 4) providing engineering faculty, students, and staff with services such as graphics and audiovisual support and typing and editing of proposals and scholarly works; 5) promoting faculty and staff development through travel and seed project support, incentive stipends, and publicity related to engineering faculty, students, and programs; 6) developing innovative methods by which the College of Engineering can increase its effectiveness in providing high quality educational opportunities for those with whom it has contact; and 7) providing a source of timely and accurate data that reflect the variety and depth of contributions made by the faculty, students and staff of the College of Engineering to the overall success of the University in meeting its mission.Through these activities, the BER serves as a unit dedicated to assisting the College of Engineering faculty by providing significant and quality service activities. ABSTRACTAn integral transform analysis of the static and time-harmonic scattering of the scalar ...

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“…The ray geometry for the field DD at and is depicted in Fig. 1 with the distance between the two diffraction points and , and the azimuthal coordinate of measured in the system at edge 1 (2). TD and FD quantities are related by the Fourier transform pair (2) (3) and a caret tags time-dependent quantities.…”

Section: Dd Field Spectral Synthesismentioning

confidence: 99%

Time domain double diffraction at a pair of coplanar skew edges

Capolino

Albani

IEEE Antennas and Propagation Society International Symposium. Transmitting Waves of Progress to the Next Millennium. 2000 Dige

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Abstract-This study aims at describing the field propagation in terms of pulsed rays, that are particularly advantageous when dealing with short-pulse excitations. In the framework of the Geometrical Theory of Diffraction we augment Geometrical Optics and uniform singly diffracted field solutions available in the time domain (TD), by TD doubly diffracted (DD) rays, that are expressed in simple closed forms. Impulsive double diffraction at a pair of coplanar edges is here formulated directly in the TD, as a double superposition of impulsive spherical waves. Nonuniform and uniform wavefront approximations for TD-DD fields are determined in closed form, defining two novel TD transition functions. The scalar case with either hard or soft boundary conditions is analyzed first, and then used to build an electromagnetic dyadic DD coefficient for a pair of coplanar edges with perfectly conducting faces. Particular attention is given to the definition of TD transition regions, i.e., the elliptical regions where the TD-DD field does not exhibit a ray optical behavior. The compensation mechanism by which the TD-DD fields repair the discontinuity introduced by singly diffracted fields at their shadow boundaries is also analyzed in detail. Our result for the TD-DD field excited by an impulsive spherical wave is valid only for early times, at and close to (behind) the DD ray wavefront. The TD-DD field response to a more general pulsed excitation is obtained via convolution, and if the exciting signal has no low-frequency components the range of validity of the resulting pulsed response is enlarged to later observation times behind the wavefront.

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Diffraction of the Pulsed Field from an Arbitrarily Oriented Electric or Magnetic Dipole by a Perfectly Conducting Wedge

Cited by 31 publications

References 3 publications

Time-domain three-dimensional diffraction by the isorefractive wedge

Time-domain three-dimensional diffraction by the isorefractive wedge

Acoustic or Electromagnetic Scattering from the Penetrable Wedge

Time domain double diffraction at a pair of coplanar skew edges

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