Noise power

In

1. The measured total noise in a given bandwidth at the input or output of a device when the signal is not present; the integral of noise spectral density over the bandwidth
2. The power generated by a random electromagnetic process.
3. Interfering and unwanted power in an electrical device or system.
4. In the
   antenna transmission line by a radio transmitter when loaded with noise having a Gaussian amplitude-vs.-frequency
   distribution.

Noise power can be calculated by multiplying the noise spectral density with the signal bandwidth

${\displaystyle N_{\text{p}}=k_{\text{B}}TB,}$

where

• k_B = Boltzmann constant ≈ 1.38×10⁻²³ J⋅K^−1[1]
• T = absolute temperature of the device
• B = bandwidth

References

 This article incorporates public domain material from Federal Standard 1037C. General Services Administration. Archived from the original on 2022-01-22. (in support of MIL-STD-188).