ABSORPTION(1) Absorbing light waves. Does not allow any reflection or refraction.
(2) Atmospheric absorption of rf energy with no reflection or refraction (adversely affects long
ACOUSTICSThe science of sound.
AMPLITUDEThe portion of a cycle measured from a reference line to a maximum value above (or to
a maximum value below) the line.
ANGLE OF INCIDENCEThe angle between the incident wave and the normal.
ANGLE OF REFLECTIONThe angle between the reflected wave and the normal.
ANGLE OF REFRACTIONThe angle between the normal and the path of a wave through the second
ANGSTROM UNITThe unit used to define the wavelength of light waves.
ANISOTROPICThe property of a radiator to emit strong radiation in one direction.
ANTENNAA conductor or set of conductors used either to radiate rf energy into space or to collect rf
energy from space.
ARRAY OF ARRAYSSame as COMBINATION ARRAY.
BAYPart of an antenna array.
BEVERAGE ANTENNAA horizontal, longwire antenna designed for reception and transmission of
low-frequency, vertically polarized ground waves.
BIDIRECTIONAL ARRAYAn array that radiates in opposite directions along the line of maximum
BROADSIDE ARRAYAn array in which the direction of maximum radiation is perpendicular to the
plane containing the elements.
CENTER-FEED METHODConnecting the center of an antenna to a transmission line, which is then
connected to the final (output) stage of the transmitter.
CHARACTERISTIC IMPEDANCEThe ratio of voltage to current at any given point on a
transmission line. Represented by a value of impedance.
COAXIAL LINEA type of transmission line that contains two concentric conductors.
COLLINEAR ARRAYAn array with all the elements in a straight line. Maximum radiation is
perpendicular to the axis of the elements.
COMBINATION ARRAYAn array system that uses the characteristics of more than one array.