Glossary

Elementary electric dipole (Hertzian dipole)

The elementary electric dipole consists of a straight wire conductor through which flows a current with sinusoidal time variations, uniformly distributed over the longitudinal dimension of the conductor.

Elementary magnetic dipole (small loop antenna)

The elementary magnetic dipole consists of a small loop through which a sinusoidal time-varying current flows, uniformly distributed around the perimeter of the loop. The elementary magnetic dipole represents the dual of the elementary electric dipole.

Near field

The near-field produced by an elementary dipole or antenna is contained in a spherical volume centered on this source and having a radius smaller than the wavelength.

Far field