Method and system for phase jitter and phase noise measurements using oscilloscopes

A system for measuring the phase jitter and phase noise of a signal-under-test (SUT), the system comprising:

• first and second oscilloscopes each having a timebase reference oscillator, the timebase reference oscillator of each of the first and second oscilloscopes configured to generate a timebase reference signal of a given output frequency;
• wherein the timebase reference oscillators of the first and second oscilloscopes are phase-locked together;
• wherein an input channel of the first oscilloscope and to an input channel of the second oscilloscope are each configured to receive the SUT;
• wherein the first oscilloscope is configured to generate a first phase jitter measurement of the SUT and the second oscilloscope is configured to generate a second phase jitter measurement of the SUT;
• and
• wherein the phase jitter and phase noise of the SUT corresponds to a cross-correlation of the first and second phase jitter measurements.

A method for measuring the phase jitter and phase noise of a signal-under-test (SUT), comprising:

• providing first and second oscilloscopes each having a timebase reference oscillator, the timebase reference oscillator of each of the first and second oscilloscopes configured to generate a timebase reference signal of a given output frequency;
• phase-locking the timebase reference oscillators of the first and second oscilloscopes together;
• applying the SUT to an input channel of the first oscilloscope and to an input channel of the second oscilloscope;
• generating a first phase jitter measurement of the SUT using the first oscilloscope and generating a second phase jitter measurement of the SUT using the second oscilloscope;
• and
• obtaining the phase jitter and phase noise of the SUT from the first and second phase jitter measurements,
• wherein obtaining the phase jitter and phase noise of the SUT comprises cross-correlating the first and second phase jitter measurements to obtain the cross-correlated phase jitter and phase noise of the SUT.