Measuring phase noise – Atec Agilent-8563E User Manual
Page 86
ESG Family Signal Generators
Performance Tests
21. Measuring Phase Noise and Residual FM (ESG-AP and ESG-DP Series Signal Generators)
Calibration Guide
4-37
21. Measuring Phase Noise and Residual FM
(ESG-AP and ESG-DP Series Signal Generators)
The signal generator’s automated performance tests do not include a test for either phase
noise or residual FM. These tests must be done separately and the results attached to the
test results obtained with the performance test software. Either output a plot for each
measured frequency, or copy the data onto the test record provided on
Measure phase noise and residual FM on an HP/Agilent E5500 system or its equivalent, at
0.5, 1, 2, 3, and 4 GHz as applicable to the model under test.
Measuring Phase Noise
Because of the excellent phase noise performance of ESG-P series signal generators, a
special procedure and extensive equipment is required. The recommended method is to use
an HP/Agilent E5500 series phase noise measurement system. This system is
recommended over the older HP/Agilent 3048 system due to speed issues and the fact that
the older system can not directly measure residual FM. Most of the rest of this discussion
refers to the E5500 system, although the principles apply to both.
The limitation of any measurement of phase noise is that the resulting measurement can
never be better than the phase noise of the source used to down-convert the signal. In an
E5500 system this source is typically either an HP/Agilent 8644B or an
HP/Agilent 8662A/63A. Both have advantages and disadvantages. The 8644B has better
phase noise above 10 kHz from the carrier, while the 8662/3 has better close-in phase
noise, but is worse above 10 kHz. Other sources may have different characteristics. To fully
characterize a signal generator to a high degree of accuracy, both sources may be needed.
The following sections illustrate three different measurements of the same device under
test (DUT):
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“Using an HP/Agilent 8663A Synthesizer”
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