By Friis's definition, noise figure (NF) and noise factor (F) are measures of degradation of the signal-to-noise ratio ( SNR), between the input and output of a component or an entire signal chain. F is the ratio of input to output SNR. These figures of merit are used to evaluate the performance of an amplifier or a radio receiver, with lower values indicating. Noise is accumulated in the optical channel due to RIN, MPN, Optical Amplifier Noise and Shot Noise. SNR. Three different methods to measure noise figure are presented: Gain method, Y-factor method, and the Noise Figure Meter method. The three approaches are compared in a table.
[PDF Version]