Noise figure (NF) and noise factor (F) are measures of degradation of the signal-to-noise ratio (SNR), caused by components in a radio frequency (RF) signal chain. It is a number by which the performance of a radio receiver can be specified.
The noise factor is defined as the ratio of the output noise power of a device to the portion thereof attributable to thermal noise in the input termination at standard noise temperature T0 (usually 290 K). The noise factor is thus the ratio of actual output noise to that which would remain if the device itself did not introduce noise, or the ratio of input SNR to output SNR.
The noise figure is simply the noise factor expressed in decibels (dB).
Read more about Noise Figure: General, Definition
Famous quotes containing the words noise and/or figure:
“While we were thus engaged in the twilight, we heard faintly, from far down the stream, what sounded like two strokes of a woodchopper’s axe, echoing dully through the grim solitude.... When we told Joe of this, he exclaimed, “By George, I’ll bet that was a moose! They make a noise like that.” These sounds affected us strangely, and by their very resemblance to a familiar one, where they probably had so different an origin, enhanced the impression of solitude and wildness.”
—Henry David Thoreau (1817–1862)
“We’ve got to figure these things a little bit different than most people. Y’know, there’s something about going out in a plane that beats any other way.... A guy that washes out at the controls of his own ship, well, he goes down doing the thing that he loved the best. It seems to me that that’s a very special way to die.”
—Dalton Trumbo (1905–1976)