The Distribution of Amplitude with Time in Fluctuation Noise

The purpose of this paper is to show that fluctuation noise has a statistical distribution of amplitude versus time which follows the normal-error law. This fact is also correlated with the measurements of crest factor made on the noise output of band-pass amplifiers by various investigators. It is shown that the distribution of noise amplitude continues to follow the normal-error law, even after the noise has been passed through frequency-selective circuits. It is shown why the measurements of crest factor, made by various experimenters, group around the value 4, but it is pointed out that this is not a true crest factor because the voltage occasionally goes considerably higher. The ratio of the average to the effective voltage is shown to be 0.798. A discussion is given of the kinds of noise which do not follow this normal-error law.