Time-domain three-dimensional diffraction by the isorefractive wedge

Author

Scharstein, Robert W. ; Davis, Anthony M J

Author_Institution

Dept. of Electr. Eng., Alabama Univ., Tuscaloosa, AL, USA

Volume

46

Issue

8

fYear

1998

fDate

8/1/1998 12:00:00 AM

Firstpage

1148

Lastpage

1158

Abstract

The extension of the Biot-Tolstoy (1957) 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, 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

Keywords

boundary-value problems; differential equations; electromagnetic fields; electromagnetic wave diffraction; electromagnetic wave scattering; geometrical optics; integral equations; time-domain analysis; Biot-Tolstoy exact time domain solution; EM isorefractive wedge; Hertzian electric dipole; Lorentz gauge; TM field; arrival times ratio; boundary value problems; differential equations; diffracted field; diffracted fields; electromagnetic isovelocity wedge; geometrical optics; impulsive terms; integral equations; magnetic field; metric-related variable; scalar potential; switch-on terms; time-domain three-dimensional diffraction; transient EM field scattering; vector potential; Acoustic diffraction; Boundary value problems; Electromagnetic diffraction; Electromagnetic scattering; Geometrical optics; Impedance; Magnetic fields; Optical diffraction; Tellurium; Time domain analysis;

fLanguage

English

Journal_Title

Antennas and Propagation, IEEE Transactions on

Publisher

ieee

ISSN

0018-926X

Type

jour

DOI

10.1109/8.718569

Filename

718569