Title :
Time-domain study of half-space transmission problem with vertical and horizontal dipoles
Author :
Nikoskinen, Keijo I.
Author_Institution :
Electromagn. Lab., Helsinki Univ. of Technol., Espoo, Finland
fDate :
10/1/1993 12:00:00 AM
Abstract :
The paper deals with the transient fields transmitted through the interface between the air and ground. Excitation for the electromagnetic fields is produced by a vertically or horizontally oriented impulsive dipole, which may be electric or magnetic. However, only electric sources are discussed, because the analog results for magnetic sources are obtained easily through the duality transform. The ground medium has arbitrary permittivity and permeability, but it is restricted to lossless, i.e. the conductivity is assumed to be zero. In this study simple integral expressions are derived for the time-dependent Hertz vector in the ground from which the propagating transient fields can be obtained through differentiation. In certain specific cases some components of electric or magnetic field have a closed-form solution in terms of elementary functions. All the nontrivial solutions of this type in the ground medium are given
Keywords :
antenna theory; dipole antennas; electromagnetic fields; integral equations; magnetic permeability; permittivity; time-domain analysis; transients; air-ground interface; closed-form solution; differentiation; duality transform; electric field; electric sources; electromagnetic fields; ground medium; half-space transmission; horizontal dipoles; impulsive dipole; integral expressions; magnetic field; nontrivial solutions; permeability; permittivity; time-dependent Hertz vector; time-domain study; transient fields; vertical dipoles; Closed-form solution; Conductivity; Electromagnetic fields; Electromagnetic transients; Geometry; Image analysis; Permeability; Permittivity; Time domain analysis; Tomography;
Journal_Title :
Antennas and Propagation, IEEE Transactions on