In electronics, noise temperature is one way of expressing the level of available noise power introduced by a component or source. The power spectral density of the noise is expressed in terms of the temperature (in kelvins) that would produce that level of Johnson–Nyquist noise, thus:
where:
- is the power (in watts)
- is the total bandwidth (Hz) over which that noise power is measured
- is the Boltzmann constant (1.381×10−23 J/K, joules per kelvin)
- is the noise temperature (K)
Thus the noise temperature is proportional to the power spectral density of the noise, . That is the power that would be absorbed from the component or source by a matched load. Noise temperature is generally a function of frequency, unlike that of an ideal resistor which is simply equal to the actual temperature of the resistor at all frequencies.
Read more about Noise Temperature: Noise Voltage and Current, Application To Communication Systems, Noise Figure, Noise Temperature of An Amplifier Chain
Famous quotes containing the words noise and/or temperature:
“I’ve almost gained my heav’nly home; My spirit loudly sings;
The holy ones behold they come, I hear the noise of wings.
O come, angel band, Come and around me stand.
O bear me away on your snowy wings, To my immortal home.”
—T. Haskell, minister and hymn-writer. Published in Christian Harmony. “Angel Band,” l. 5-8.
“The siren south is well enough, but New York, at the beginning of March, is a hoyden we would not care to miss—a drafty wench, her temperature up and down, full of bold promises and dust in the eye.”
—E.B. (Elwyn Brooks)