Calculate Noise Figure (NF) and Noise Factor (F) for electronic systems.
System Parameters
Calculate from SNR:
OR
Calculate from Temp:
K
Calculation Results
Enter SNR values or Noise Temperature
About this calculator
Quick Reference
NFNoise Figure (dB)
FNoise Factor (linear)
TₑEquivalent Noise Temp (K)
T₀Standard Reference Temp (290K)
Overview
Noise Figure (NF) is a measure of degradation of the signal-to-noise ratio (SNR), caused by components in a signal chain. It is the ratio of actual output noise to that which would remain if the device itself did not introduce noise.
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Pro Tips
A perfect (noiseless) amplifier has a Noise Figure of 0 dB.
Noise Factor is the linear version of Noise Figure.
The Friis formula is used to calculate the total noise figure of a cascaded system.
Lower Noise Figure is always better in receiver design.
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Fun Facts
"Noise Figure is usually measured with a noise source and a spectrum analyzer."
"Even a piece of wire can contribute thermal noise (Johnson-Nyquist noise)."
"Liquid nitrogen or helium cooling is often used in sensitive radio telescopes to reduce the Noise Figure."
