Modulation

An unmodulated carrier is a constant amplitude, single-frequency, sinusoidal wave. A carrier wave must be varied in some way to transmit intelligence. The process of varying a carrier wave to superimpose intelligence is known as modulation. Despite all the apparent forms of modulation, there are only two fundamental forms. They are variations in amplitude and variations in repetition rate (phase or frequency). All the more complex forms of modulation, including spread spectrum, actually are variations or combinations of these two fundamental forms. ©2004 Tigertek, Inc. All rights reserved.

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