Equivalent noise resistance

In telecommunications, an equivalent noise resistance is a quantitative representation in resistance units of the spectral density of a noise-voltage generator, given by $R_n=\frac{\pi W_n}{k{T}_0}$ where $W_n$ is the spectral density, $k$ is the Boltzmann constant, $T_0$ is the standard noise temperature (290 K), so $k{T}_0=4.00\times 10^{-21}[Ws]$.

Note: The equivalent noise resistance in terms of the mean-square noise-generator voltage, e², within a frequency increment, Δ f, is given by

$R_n=\frac{e^2}{4k{T}_0\mathrm{\Delta }f}.$

See also

• Equivalent input noise
• Effective input noise temperature