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Absolute Measurement Fundamentals
5
Agilent E5505A User’s Guide
111
The Noise Level of the Reference Source
Unless it is below the system’s noise floor, the noise level of the source you are
using as the reference source sets the noise floor for the measurement. When
you set up your measurement, you want to use a reference source with a noise
level that is at or below the level of the source you are going to measure.
demonstrates that as the noise level of the reference source
approaches the noise level of the DUT, the level measured by the System
(which is the sum of all noise sources affecting the system) is increased above
the actual noise level of the DUT.
Figure 75
Reference source noise approaches DUT noise
15
10
5
4
3
2
1
0.5
1.0
1.5
2.0
2.5
3.0
E5505a_inc_meas_noise
26 Feb 04 rev 1
Amount expected DUT noise exceeds reference noise (dB)
Increase in measured noise due
to reference noise (dB)
Summary of Contents for E1420B
Page 24: ...24 Agilent E5505A User s Guide ...
Page 46: ...46 Agilent E5505A User s Guide 2 Introduction and Measurement ...
Page 128: ...128 Agilent E5505A User s Guide 5 Absolute Measurement Fundamentals ...
Page 226: ...226 Agilent E5505A User s Guide 7 Residual Measurement Fundamentals ...
Page 322: ...322 Agilent E5505A User s Guide 13 Baseband Noise Measurement Examples ...
Page 340: ...340 Agilent E5505A User s Guide 14 Evaluating Your Measurement Results ...
Page 358: ...358 Agilent E5505A User s Guide 15 Advanced Software Features ...
Page 386: ...386 Agilent E5505A User s Guide 16 Reference Graphs and Tables ...
Page 392: ...392 Agilent E5505A User s Guide 17 System Specifications ...
Page 404: ...404 Agilent E5505A User s Guide 18 System Interconnections ...
Page 452: ...452 Agilent E5505A User s Guide 20 PC Digitizer Performance Verification ...
Page 466: ...466 Agilent E5505A User s Guide 21 Preventive Maintenance ...