modulation factor

modulation factor

[‚mäj·ə′lā·shən ‚fak·tər] (communications) In general, the ratio of the peak variation in the modulation actually used in a transmitter to the maximum variation for which the transmitter was designed. In an amplitude-modulated wave, the ratio (usually expressed in percent) of the peak variation of the envelope from its reference value, to the reference value. Also known as index of modulation. In a frequency-modulated wave, the ratio of the actual frequency swing to the frequency swing required for 100% modulation.