Keysight Technologies N5511A, User Manual

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96 N5511A Phase Noise Test System User’s Guide
Absolute Measurement Fundamentals
Calibration
Figure 5-32 Double-Sided Spur Method
When measuring phase noise, the carrier is modulated with a known PM
depth. This value relative to the carrier as well as the modulating rate is
entered in the software under the Cal tab.
In the example in
Figure 5-33 , the system measures a tone at -40 dBc
Figure 5-33 Known Spur Parameters
The system is phase locked and the modulating tone measured. In this case,
the tone is a double-sideband PM tone so there is no AM to reject, so the
entered value in the application is used to determine the amplitude of the
carrier.