Amplitude modulation

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noun
one of the princ-p-l methods of transmitting audio, visual, or other types of information using radio waves, the relevant signal being superimposed onto a radio-frequency carrier wave. the frequency of the carrier wave remains unchanged but its amplitude is varied in accordance with the amplitude of the input signal abbreviation am, am compare frequency modulation
a wave that has undergone this process
amplitude modulation
a method of transmitting signals, such as sound or digital information, in which the value of the signal is given by the amplitude of a high frequency carrier wave. in am radio transmission, for example, the signal to be carried is a sound wave, and its increasing and decreasing value is reflected in the increasing and decreasing amplitude of the radio frequency carrier wave. in fiber optics, the carrier wave is a beam of light. compare frequency modulation.
amplitude modulation (am)

a type of radio signal in which the amplitude, or strength, of a radio wave is varied in order to carry information from a transmitter to a receiver. (compare frequency modulation (fm).)

communications
(am) a method of encoding data by varying the amplitude of a constant frequency carrier.
contrast frequency modulation.
(2001-04-30)