5: Configuring Data Displays; Configuring Phase Noise Plot - Symmetricom 5120A Operation And Maintenance Manual

5: Configuring Data Displays

5.1 Configuring Phase Noise Plot

The 5120A and 5120A-01display (f) phase noise data out to 1 MHz, provided neither the input
nor reference signal is below 2 MHz. The 5115A displays data out to 100 kHz. This data shows the
(f) spectrum of the phase differences between the Input and Reference signals. All measurements
are referenced to the frequency of the Input signal.
Data first displays on the screen after collection starts, then the screen updates as often as a few
times per second. The first range of data displayed is from approximately 0.1 Hz to the maximum.
The longer the data collection period, the more data is available to display phase noise at lower
offset frequencies.
The test set detects spurs caused by its own operation. These spurs are referred to as internally
generated spurs. Internally generated spurs are removed from calculations. All spurs plotted on the
phase noise plot are part of the signals attached to Input or Reference port.
Figure 9 Example Phase Noise Plot shows an example phase noise plot.
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