Agilent Technologies N9010A specifications General Specifications, 154

Noise Figure Measurement Application

General Specifications

General Specifications

Description	Specifications		Supplemental Information
Noise Figure			Uncertainty Calculatora
≤10 MHzb
10 MHz to 3.6 GHz			Using internal preamp
			(Option P03) and
			RBW = 4 MHz
Noise Source ENR	Measurement	Instrument
	Range	Uncertaintycd
4 − 6.5 dB	0 to 20 dB	±0.02 dB
12 − 17 dB	0 to 30 dB	±0.025 dB
20 − 22 dB	0 to 35 dB	±0.03 dB
Above 3.6 GHz			Not Recommendede

a.The figures given in the table are for the uncertainty added by the X-Series Signal Analyzer instrument only. To compute the total uncertainty for your noise figure measurement, you need to take into account other factors including: DUT NF, Gain and Match, Instrument NF, Gain Uncertainty and Match; Noise source ENR uncertainty and Match. The computations can be performed with the uncertainty calcula- tor included with the Noise Figure Measurement Personality. Go to Mode Setup then select Uncertainty Calculator. Similar calculators are also available on the Agilent web site; go to http://www.agi- lent.com/find/nfu.

b.Instrument Uncertainty is nominally the same in this frequency range as in the higher frequency range. However, total uncertainty is higher because the analyzer has poorer noise figure, leading to higher uncertainties as computed by the uncertainty calculator. Also, there is a paucity of available noise sources in this range.

c.“Instrument Uncertainty” is defined for noise figure analysis as uncertainty due to relative amplitude uncertainties encountered in the analyzer when making the measurements required for a noise figure computation. The relative amplitude uncertainty depends on, but is not identical to, the relative display scale fidelity, also known as incremental log fidelity. The uncertainty of the analyzer is multiplied within the computation by an amount that depends on the Y factor to give the total uncertainty of the noise figure or gain measurement.

See Agilent App Note 57-2, literature number 5952-3706E for details on the use of this specification. Jitter (amplitude variations) will also affect the accuracy of results. The standard deviation of the mea- sured result decreases by a factor of the square root of the Resolution Bandwidth used and by the square root of the number of averages. This application uses the 4 MHz Resolution Bandwidth as default since this is the widest bandwidth with uncompromised accuracy.

d.The instrument uncertainties shown are under best-case sweep time conditions, which is a sweep time near to the period of the power line, such as 20 ms for 50 Hz power sources. The behavior can be greatly degraded (uncertainty increased nominally by 0.12 dB) by setting the sweep time per point far from an integer multiple of the period of the line frequency.

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