Definition of amplitude modulation in English:

amplitude modulation

(also AM)


  • [mass noun] The modulation of a wave by varying its amplitude, used especially as a means of broadcasting an audio signal by combining it with a radio carrier wave.

    Often contrasted with frequency modulation
    • ‘This is consistent with the pronounced amplitude modulation of the shorter cycles noted above.’
    • ‘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.’
    • ‘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.’
    • ‘A controller selectively controls the first and second transistors to achieve amplitude modulation at a high modulation bandwidth.’
    • ‘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.’