IEVref: 702-08-59 ID: Language: en Status: Standard Term: (mean) noise factor (of a linear two-port device) Synonym1: (mean) noise figure (of a linear two-port device) [Preferred] Synonym2: Synonym3: Symbol: $\overline{F}$ Definition: the ratio of the total noise power appearing at the output of a given linear two port device within a specified frequency band, to the portion of this power originating from the one-port device connected to the input of the two port device, the noise temperature of the one-port device being assumed equal at all frequencies to the reference thermodynamic temperature conventionally fixed around 290 K NOTE 1 – The mean noise factor $\overline{F}$ is related to the mean noise temperature T as follows: $\overline{F}=1+\frac{\overline{T}}{{T}_{0}}$ where T0 is the reference thermodynamic temperature. NOTE 2 – The value of the mean noise factor may be expressed in decibels. In English the term "noise factor" is generally employed when the ratio is expressed arithmetically and "noise figure" is employed when the ratio is expressed in decibels. Publication date: 1992-03 Source: Replaces: Internal notes: 2015-12-04: To corrected to T0. JGO 2016-01-29: In Note 1 "symb.:" deleted to align with fr (is also superfluous). JGO 2017-06-02: Cleanup - Remove Attached Image 702-08-59.gif 2017-06-02: Cleanup - Remove Attached Image 702-08-59-symb.gif CO remarks: TC/SC remarks: VT remarks: Domain1: Domain2: Domain3: Domain4: Domain5: