Agilent Technologies E5500 Phase Noise Measurement System
6-23
Absolute Measurement Fundamentals
Evaluating Noise Above the Small Angle Line
Figure 6-13
Graph Showing Peak Tuning Range Requirements for Noise that Exceeds
the Small Angle Limit
Measurement Options
If the observed level exceeded the small angle line at any point beyond the
PLL bandwidth set for the measurement, you will need to consider one of
the following measurement options.
1. Evaluate your source using the noise data provided by the RF analyzer
in the procedure you just performed.
2. Increase the PTR if possible, to provide a sufficient PLL bandwidth to
suppress the noise. (For information on increasing the PTR, refer to
Changing the PTR in this section.)
3. Reduce the noise level of the signal sources.
4. Use the Discriminator technique to measure the phase noise level of
your source.
