bandwidth, in electronics, the range of frequencies occupied by a modulated radio-frequency signal, usually given in hertz (cycles per second) or as a percentage of the radio frequency. For example, an AM (amplitude modulation) broadcasting station operating at 1,000,000 hertz has a bandwidth of 10,000 hertz, or 1 percent (10,000/1,000,000). The term also designates the frequency range that an electronic device, such as an amplifier or filter, will transmit.