Agilent ADS question phase noise measurements

[vinetic]

how does agilent ads calculate phase noise

i'm try to use Agilent ADS 2009...

I'm started from some tutorials from rfic.co.uk, but i'm have some problems with Colpitts Oscillator:

i'm dont understand why my ads at phase noise prediction have -56@10khz but in tutorial -120... I'm found that from ads 2005 theris no pnfm.
Whats defferents with pnfm and pnmx ?

 

[vinetic]

agilent ads phase noise

I'm attached project folder...

 

[N1UL]

phase in agilent ads

General comments on noise :

The early oscillator pioneers like Leeson, Driscoll, Healey III , Parker and others did their analysis based on linear assumptions, which do not get the same good results as available today. The modern methods require large signal parameters which Agilent now calls X parameters. Provided that the input parameters for the models are OK, the harmonic balance simulators can tackle this. I prefer measurements , using a network analyzer and then a set of analytic equations. The results for modern planar resonator based oscillators up to 20 GHz are much better then the conventional predictions without dealing with the conduction angle of the current and suppressing or even enhancing certain harmonics

This modern approach, heavily depending on non liner analysis and mathematics shows a further improvement, by reducing the AM to PM conversion, both modulation and conversion noise (close in and far out noises are different in their origin).

It applies both for crystal oscillators and printed resonators and other solutions. I will follow up with a series of IEEE publication and validations , but the curious readers may find the basic presentations useful.
The Design of Modern Microwave Oscillators for Wireless Applications, by Ulrich L. Rohde, Ajay K. Poddar, Georg Böck, published by John Wiley & Sons, New York, NY, May, 2005, ISBN 0-471-72342-8.