# Phase Noise Analysis

Subtopics

- Clock Signal Probing Options
- Setting Up Phase Noise Analysis Sources
- Setting Up Phase Noise Analysis Measurements
- Viewing the Phase Noise Analysis Acquisition Settings
- Scaling the Phase Noise Analysis Display
- Viewing the Phase Noise Analysis Results
- Phase Noise Analysis Overview

The Phase Noise analysis feature measures phase noise in a clock source. It can use the two-channel cross-correlation technique that lowers the oscilloscope's phase noise measurement floor by splitting the clock source signal into two oscilloscope input channels (see Clock Signal Probing Options).

As the oscilloscope runs, continuing to make acquisitions, a specified number of cross-correlations are performed to reduce noise. After the specified number of cross-correlations are performed, measurement results are averaged to smooth the roughness of the phase noise plot.

Phase noise measurement results are presented in a log frequency plot where the amplitude units are dBc/Hz (decibels relative to the carrier power normalized to a 1 Hz bandwidth). The X-axis is the single-sideband (SSB) frequency offset from the nominal signal or "carrier" frequency.

## First

- Setting Up Phase Noise Analysis Sources