Definition for "Noise Figure" in the Quantum Dictionary

Engineering & Applied Technologies Dictionary

Noise figure (NF), expressed in decibels, is the device or component parameter that quantifies the degradation of signal‑to‑noise ratio (SNR) caused by that device: NF(dB)=10·log10(F) where noise factor F = SNRin / SNRout for specified input termination and measurement conditions.

Information & Communication Dictionary

A scalar measure of how much a receiver or amplifier degrades the signal-to-noise ratio (SNR) of an input signal relative to an ideal, noiseless, lossless reference. Noise figure (NF, in dB) is NF(dB) = 10·log10(F) where the noise factor F = SNR_in / SNR_out (linear SNRs); it refers device-added noise to the input and is specified for a given bandwidth, source impedance, frequency and temperature.