Atec Agilent-8563E - Manual (Page 87)

Performance Tests ESG Family Signal Generators
21. Measuring Phase Noise and Residual FM (ESG-AP and ESG-DP Series Signal Generators)
4-38 Calibration Guide
Using an HP/Agilent 8644B
Figure 4-34 shows the phase noise results of the DUT using the 8644B as the
down-converting source. Note that while it has excellent phase noise above 10 kHz, the
results below 10 kHz rapidly degrade. The 60 Hz related noise spikes are typically due to
the DCFM method of phase locking the DUT to the E5500.
Figure 4-34