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Agilent E5505A User’s Guide
7
Residual Measurement Fundamentals
Assumptions about Residual Phase Noise Measurements
The following are some basic assumptions regarding Residual Phase Noise
measurements. If these assumptions are not valid they will affect the
measured results.
•
The source noise in each of the two phase detector paths is correlated at the
phase detector for the frequency offset range of interest. When the source
noise is correlated at the phase detector, the source phase noise cancels,
leaving only the residual phase noise of the DUT.
•
Source AM noise is comparatively small. A typical mixer-type phase
detector only has about 20 to 30 dB of AM noise rejection. If the AM
component of the signal is greater than 20 to 30 dB above the residual
phase noise, it will contribute to the residual phase noise measurement and
show the residual phase noise as being greater than it really is.
•
The DUT does not exhibit a bandpass filter function. A bandpass filter type
response will cause the source noise to be decorrelated at the edge of the
filter. This decorrelation of the noise causes the system to measure the
source noise level directly at offsets beyond the filter bandwidth.
Given these assumptions, when the DUT is connected to either of the two
inputs of the phase detector, all of the source noise cancels and only the
residual noise of the DUT is measured. See
Figure 146
Setup for typical residual phase noise measurement
Phase
detector
Power
splitter
Source
Base band
analysis
E5505a_typ_res_phase_noise
27 Feb 04 rev 1
Device
under
test
Содержание E1420B
Страница 24: ...24 Agilent E5505A User s Guide ...
Страница 46: ...46 Agilent E5505A User s Guide 2 Introduction and Measurement ...
Страница 128: ...128 Agilent E5505A User s Guide 5 Absolute Measurement Fundamentals ...
Страница 226: ...226 Agilent E5505A User s Guide 7 Residual Measurement Fundamentals ...
Страница 322: ...322 Agilent E5505A User s Guide 13 Baseband Noise Measurement Examples ...
Страница 340: ...340 Agilent E5505A User s Guide 14 Evaluating Your Measurement Results ...
Страница 358: ...358 Agilent E5505A User s Guide 15 Advanced Software Features ...
Страница 386: ...386 Agilent E5505A User s Guide 16 Reference Graphs and Tables ...
Страница 392: ...392 Agilent E5505A User s Guide 17 System Specifications ...
Страница 404: ...404 Agilent E5505A User s Guide 18 System Interconnections ...
Страница 452: ...452 Agilent E5505A User s Guide 20 PC Digitizer Performance Verification ...
Страница 466: ...466 Agilent E5505A User s Guide 21 Preventive Maintenance ...