Noise Figure Range And Accuracy; Test Description; Test Specification - Keysight NFA Series Performance Verification And Calibration Manual

Table 2-10
Noise Source ENR
Noise Figure Measurement Range
Instrument Uncertainty
Table 2-11
Noise Source ENR
Noise Figure Measurement Range
Instrument Uncertainty

Noise Figure Range and Accuracy

Test Description

A precision step attenuator, calibrated at 50 MHz with an accuracy of
0.010dB, is used as an external standard to measure the NFA's Noise
Figure Range and Accuracy over a 22dB range. The results are then used
to determine the Instrument Uncertainty for the given ENR values over
their respective measurement ranges.
A 50 MHz CW signal is passed through a precision step attenuator. The
signal path is referenced at 0dB attenuation. The attenuator is then
stepped in 1dB steps from 1 to 11 taking the analyzers P
measurement at each step. Only one step attenuator is used in the
measurement to reduce the overall measurement uncertainty of the
standard. It is therefore necessary to re-reference the measurement and
repeat the test covering the range from 12-22dB. All levels tested below
1dB are interpolated from the measured points, as the minimum step
attenuator setting is 1dB.
For test purposes the Noise Figure Range and Accuracy is only tested at
the lower frequency band with the most accurate specifications.

Test Specification

N8972A specification
N8973A, N8974A and N8975A specification
Chapter 2
Noise Figure Range and Accuracy
4 - 7dB 12 - 17dB
0 to 20dB 0 to 30dB
± 0.10dB ± 0.10dB
4 - 7dB 12 - 17dB
0 to 20dB 0 to 30dB
± 0.05dB ± 0.05dB
Test Descriptions
hot
20 - 22dB
0 to 35dB
± 0.15dB
20 - 22dB
0 to 35dB
± 0.10dB
55