amplitude modulation

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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.

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


(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.

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.
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
modulation d'amplitude
References in periodicals archive ?
NEC will implement 2048 Quadrature Amplitude Modulation (2048QAM) within its iPASOLINK product family in the second half of 2012.
Last year, Martini and his team at Stevens, The Innovation University[TM], developed a method to optically induce fast amplitude modulation in a quantum cascade laser - a process that allows them to control the laser's intensity.
But the team also will have access to some sophisticated equipment, including a pulse amplitude modulation fluorometer, a $13,000 piece of equipment that helps analyze how the algae utilize sunlight in photosynthesis.
Techniques for modulating UWB pulses include Pulse Position Modulation and Pulse Amplitude Modulation.
Microwave and radio-frequency (electromagnetic wave energy) heating utilize magnetron systems with on/off time-proportioning control or amplitude modulation.
NAA/NSC member WSNet announced that it now offers its network of multiple dwelling unit (MDU) service providers digital video via Quadrature Amplitude Modulation (QAM), one of the most cost-effective methods of providing 200 channels of digital satellite television to apartment complexes, condominiums, townhomes, retirement communities, nursing homes, marinas, RV parks, university dormitories and new housing developments.
This section describes in brief the underlying principles behind Amplitude Modulation, Frequency Modulation and Demodulation (Miller, 1996).

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