single sideband phase noise

Hi, Folks:

I am using eldo_rf to simulate the phase noise of ring oscillator.

It will generate report as sphi and sphi_ssb. According to definition, single side band noise should be 3db greater than double side band noise.

However, the results are reversed.
db(Sphi_dsb) = db(Sphi_ssb)+3dB;

I believe Mentor have a bug, any one know more information on this bug?

thanks

Hi,

There is no bug

L(f) that was historically called the Single Side Band phase noise spectrum
was equal to the noise power spectral density at the frequency F0 + f
(or at the frequency F0 - fp), divided by the signal power at the oscillation
frequency F0. It is called single side band because only one side (F0 + f or F0 - f)
of the noise power is taken into account.
Sphi that is also called the double side band phase noise spectrum is equal to
spectral density of the phase fluctuations.

Now if you look at the official IEEE standard definitions for L(f) and Sphi, you could
see that (Eq. 12 page 340) L(f) = Sphi / 2.

E.S. Ferre-Pikal, J.R. Vig, J.C. Camparo, L.S. Cutler, L. Maleki, W.J. Riley, S.R. Stein,
C. Thomas, F.L. Walls, and J.D. White : "Draft revision of IEEE STD 1139-1988 standard
definitions of physical quantities for fundamental frequency and time metrology - Random instabilities".
IEEE International Frequency and Control Symposium, 1997, (pp338-357)

Bozzo.