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Envelope (waves)
Smooth curve outlining the extremes of an oscillating signal / From Wikipedia, the free encyclopedia
In physics and engineering, the envelope of an oscillating signal is a smooth curve outlining its extremes.[1] The envelope thus generalizes the concept of a constant amplitude into an instantaneous amplitude. The figure illustrates a modulated sine wave varying between an upper envelope and a lower envelope. The envelope function may be a function of time, space, angle, or indeed of any variable.
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