Chapter 2
55
Test Descriptions
Noise Figure Range and Accuracy
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
hot
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
Table 2-10
N8972A specification
Noise Source ENR
4 - 7dB
12 - 17dB
20 - 22dB
Noise Figure Measurement Range
0 to 20dB
0 to 30dB
0 to 35dB
Instrument Uncertainty
±
0.10dB
±
0.10dB
±
0.15dB
Table 2-11
N8973A, N8974A and N8975A specification
Noise Source ENR
4 - 7dB
12 - 17dB
20 - 22dB
Noise Figure Measurement Range
0 to 20dB
0 to 30dB
0 to 35dB
Instrument Uncertainty
±
0.05dB
±
0.05dB
±
0.10dB
Summary of Contents for N8972A
Page 9: ...ix Declaration of Conformity N8972A ...
Page 10: ...x Declaration of Conformity N8973A ...
Page 11: ...xi Declaration of Conformity N8974A ...
Page 12: ...xii Declaration of Conformity N8975A ...
Page 19: ...Contents xix ...
Page 20: ...xx Contents ...
Page 108: ...88 Chapter2 Test Descriptions Measurement Jitter ...
Page 124: ...104 Chapter3 Technical Specifications General Specifications ...
Page 136: ...116 AppendixA Model N8972A Test Records Measurement Jitter Test Record ...
Page 148: ...128 AppendixB Model N8973A Test Records Measurement Jitter Test Record ...
Page 160: ...140 AppendixC Model N8974A Test Records Measurement Jitter Test Record ...
Page 174: ...154 AppendixD Model N8975A Test Records Measurement Jitter Test Record ...