Johnson–Nyquist Noise

Johnson–Nyquist noise (thermal noise, Johnson noise, or Nyquist noise) is the electronic noise generated by the thermal agitation of the charge carriers (usually the electrons) inside an electrical conductor at equilibrium, which happens regardless of any applied voltage. The generic, statistical physical derivation of this noise is called the fluctuation-dissipation theorem, where generalized impedance or generalized susceptibility is used to characterize the medium.

Thermal noise in an idealistic resistor is approximately white, meaning that the power spectral density is nearly constant throughout the frequency spectrum (however see the section below on extremely high frequencies). Additionally, the amplitude of the signal has very nearly a Gaussian probability density function.

Read more about JohnsonNyquist NoiseHistory, Noise Voltage and Power, Noise Current, Noise Power in Decibels, Thermal Noise On Capacitors, Noise At Very High Frequencies

Other articles related to "noise":

Johnson–Nyquist Noise - Noise At Very High Frequencies
... In order to know the total noise it is enough to integrate over all the bandwidth ... of the voltage across a resistor due to thermal noise is given by that is, the same formula as above ...

Famous quotes containing the word noise:

    There is something terribly wrong with a culture inebriated by noise and gregariousness.
    George Steiner (b. 1929)