Modulation
Another method of conveying an analog signal is to use modulation. In this, some base signal (e.g., a sinusoidal carrier wave) has one of its properties modulated: amplitude modulation involves altering the amplitude of a sinusoidal voltage waveform by the source information, frequency modulation changes the frequency. Other techniques, such as changing the phase of the base signal also work.
Analog circuits do not involve quantisation of information into digital format. The concept being measured over the circuit, whether sound, light, pressure, temperature, or an exceeded limit, remains from end to end.
See digital for a discussion of digital vs. analog.
Sources: Parts of an earlier version of this article were originally taken from Federal Standard 1037C in support of MIL-STD-188.
Read more about this topic: Analog Signal
Famous quotes containing the word modulation:
“Every accent, every emphasis, every modulation of voice, was so perfectly well turned and well placed, that, without being interested in the subject, one could not help being pleased with the discourse; a pleasure of much the same kind with that received from an excellent piece of music. This is an advantage itinerant preachers have over those who are stationary, as the latter can not well improve their delivery of a sermon by so many rehearsals.”
—Benjamin Franklin (1706–1790)