Frequencies which are within two definite limits, the middle of which is called the CENTRE FREQUENCY.
For example, in radio transmission, the standard AM broadcasting band extends from 550 to 1600 kHz, and the FM band extends from 87 to 108 mHz. With a qualifying adjective, the term can refer to a certain RANGE of frequencies roughly described by the adjective, e.g. BROAD BAND NOISE, NARROW BAND NOISE.
See: chart under RADIO SPECTRUM. See also: BANDWIDTH, CRITICAL BAND, EQUALIZATION, FILTER, MASS, WHITE NOISE. Compare: SIDEBAND.