amplitude modulation

Also found in: Thesaurus, Medical, Legal, Financial, Acronyms, Encyclopedia, Wikipedia.
Related to amplitude modulation: phase modulation, frequency modulation

amplitude modulation

n. Abbr. AM
1. The encoding of a carrier wave by varying its amplitude in accordance with an input signal.
2. A broadcast system that uses amplitude modulation.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

amplitude modulation

1. (Telecommunications) 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 signal. Abbreviation: AM or am Compare frequency modulation
2. (Telecommunications) a wave that has undergone this process
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(æm; unstressed əm, m)

1st pers. sing. pres. indic. of be.
[before 900; Old English am, eam, eom]


1. Asian male.
2. amplitude modulation: a method of impressing a signal on a radio carrier wave by varying its amplitude.
3. a system of broadcasting using this method.
Compare FM.


Chem. Symbol.


1. America.
2. American.


Master of Arts.
[< Latin Artium Magister]


or A.M.,

1. before noon.
2. the period from midnight to noon, esp. the period of daylight prior to noon.
Compare p.m.
[1755–65; < Latin ante merīdiem]
usage: The abbreviation a.m. refers to the period from midnight until noon. One minute before noon is 11:59 a.m. One minute after noon is 12:01 p.m. Many people distinguish between noon and midnight by saying 12 noon and 12 midnight. Expressions such as 6 a.m. in the morning and 9 p.m. at night are redundant.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.

amplitude modulation

A method of radio broadcasting in which the amplitude of the wave that carries the sound signal changes to reflect the various sounds that are to be reproduced, while the frequency of the wave remains the same. Compare frequency modulation.
The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.amplitude modulation - modulation of the amplitude of the (radio) carrier waveamplitude modulation - modulation of the amplitude of the (radio) carrier wave
modulation - (electronics) the transmission of a signal by using it to vary a carrier wave; changing the carrier's amplitude or frequency or phase
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
modulation d'amplitude
References in periodicals archive ?
Quadrature amplitude modulation has a major application in various digital radio communications and data communications.
The second one was chosen due to the fact that it is an analytically derived solution for a damped sinusoid [6], and a damped sinusoid could be modeled with good accuracy by amplitude modulation [9]--it will be called RVCI (Rife-Vincent Class I).
Uplink carrier aggregation with two carriers is expected to double peak upload data speeds to 102Mbps and downlink 256 Quadrature Amplitude Modulation (QAM) support will supposedly boost subscribers' download peak performance by more than 30%.
The amplitude modulation term [m.sub.a] and the frequency modulation term [m.sub.f] can be described as [16-17]:
Even tremor, vibrato, and register are first defined perceptually before they are cast into production terminology like amplitude modulation, frequency modulation, or spectral tilt.
It requests "robust protection for existing wind farm neighbours against the effects of turbine noise - specifically against Excessive Amplitude Modulation (EAM).
Their main focus is on digital communications bit error rate (BER) performance in additive white Gaussian noise (AWGN), which they consider in terms of binary, quaternary, binary, and multi-phase shift keying; quadrature amplitude modulation; frequency shift-keying; minimum-shift keying; space-time block coding; and other contexts.
Gordon's lab has pioneered the use of paired nanoscale apertures to trap such samples optically; the amplitude modulation between two lasers of different frequencies effectively creates very fine tweezers for holding small particles.
The shape of the grating response suggests that the tuning bandwidth could be used for amplitude modulation (AM) applications or band-pass filters.

Full browser ?