noun Electronics, Radio.
Origin of amplitude modulation
First recorded in 1920–25
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
one of the principal 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 signalAbbreviation: AM, am Compare frequency modulation
a wave that has undergone this process
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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.
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