TC 9-64 _________________________________________________________________________
smaller basic frequency. For example, a radio wave transmitted at a
fundamental frequency of 3000 hertz can have a second harmonic of 6000
A vertically polarized antenna transmits an electromagnetic wave with the E
field perpendicular to the earth's surface. A horizontally polarized antenna
transmits a radio wave with the E field parallel to the earth's surface.
A wavefront is a small section of an expanding sphere of radiated energy and
is perpendicular to the direction of travel from the antenna.
Radio waves are electromagnetic waves that can be reflected, refracted, and
diffracted in the atmosphere in the same manner as light and heat waves.
Reflected radio waves are waves that have been reflected from a surface and
are 180 degrees out of phase with the initial wave.