Excess noise ratio
From Wikipedia, the free encyclopedia
Not to be confused with excess noise factor in an avalanche photodiode or other photodetector with internal gain.
In electronics, excess noise ratio is a characteristic of a noise generator such as a "noise diode", that is used to measure the noise performance of amplifiers. The Y-factor method is a common measurement technique for this purpose.[1]
By using a noise diode, the output noise of an amplifier is measured using two input noise levels, and by measuring the output noise factor (referred to as Y) the noise figure of the amplifier can be determined without having to measure the amplifier gain.