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Calculate noise figure of transmission lines, series RLC, and shunt RLC circuits

Since R2020b



nf = noisefigure(transmissionline,frequency,zs) calculate the noise figure of transmission lines using the given frequency and source impedance.


nf = noisefigure(RLCckt,frequency,zs) calculate the noise figure of series and shunt RLC circuits using the given frequency and source impedance. RLCckt is either seriesRLC or shuntRLC objects.


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Create a two-wire transmission line using these specifications:

  • Radius - 0.5 mm

  • Dielectric - air

  • Thickness of dielectric or separation - 1.088 mm

  • Permittivity or EpsilonR - 1.0054

twowiretxline = txlineTwoWire('Radius',0.5e-3,'EpsilonR',1.0054,'Separation',1.088e-3);

Calculate the noise figure and the group delay of the transmission line at 2.5 GHz.

nf = noisefigure(twowiretxline,2.5e9)
nf = 0
gd = groupdelay(twowiretxline,2.5e9)
gd = 3.3446e-11

Input Arguments

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Series or shunt RLC circuit objects, specified as a seriesRLC or shuntRLC objects.

Frequency to calculate noise figure, specified as a positive scalar in hertz.

Source impedance, specified as a positive real scalar in ohms.

Version History

Introduced in R2020b

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