Definition of amplitude modulation in US English:

amplitude modulation

(also AM)


  • The modulation of a wave by varying its amplitude, used chiefly as a means of radio broadcasting, in which an audio signal is combined with a carrier wave.

    Often contrasted with frequency modulation
    • ‘Optical systems are used to generate the original signal which is passed, using amplitude modulation to a 300GHz photodiode, which creates an electrical signal that is passed to a direct slot antenna.’
    • ‘Its phase can be adjusted to compensate for propagation delays in the drive circuitry, while amplitude modulation is accomplished by switching in additional reactive conductance to increase the current injected into the tank circuit.’
    • ‘A controller selectively controls the first and second transistors to achieve amplitude modulation at a high modulation bandwidth.’
    • ‘Even in more slowly rotating vehicles, residual phase and amplitude modulation produced by adaptive interference-canceling systems can significantly reduce GPS acquisition and tracking performance.’
    • ‘This is consistent with the pronounced amplitude modulation of the shorter cycles noted above.’


amplitude modulation

/ˈampləˌt(y)o͞od ˌmäjəˌlāSHən/