Phase noise calculation

[hmsheng]

phase noise calculation

It's a sinusoidal signal with phase fluctuations. I have the time domain phase fluctuations data. How can I calculate the phase noise according to the phase fluctuatin data?

 

[John Miles KE5FX]

Just FFT the original noisy sinewave sample, as far as I know.

 

[elbadry]

For a hand calculation you can use a small signal approx.

Suppose the signal is sin(ωt+Φ) where Φ is the noisy phase fluctuation. if Φ is very near to zero you can say that

sin(ωt+Φ) = sin(ωt)cos(Φ)+cos(ωt)sin(Φ) = sin(ωt)*1+cos(ωt)*Φ

Thus the noise amplitude will be that of Φ

 

[Hunter_BJUT]

you can calculate from PSD of jitter

 

[april1975]

John Miles KE5FX wrote:

Just FFT the original noisy sinewave sample, as far as I know.

How we can measure phase noise from the fft data file?