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Simulators >> RF Simulators >> How to perform the PSS+PNOISE for a divider?
https://designers-guide.org/forum/YaBB.pl?num=1215056515

Message started by Tucson on Jul 2^nd, 2008, 8:41pm

Title: How to perform the PSS+PNOISE for a divider?
Post by Tucson on Jul 2^nd, 2008, 8:41pm

Hi, Gentlemen,

I want to simulate the phase noise of a divider circuit, however, I'm a little confused with the PNOISE settings:

(i). How to set the output frequency range? The frequency supposed to be get after dividing?

(ii). The input frequency range? which is calculated by the simulator itself after setting the output frequency range. For example, suppose the divider ratio is 4, and the output frequency after dividing is 100M, I got the following message from the simulation log:
**********************************************************
Periodic Noise Analysis 'pnoise': freq = 100 MHz + (1 KHz -> 1 MHz)
**********************************************************
Input frequency range = 400 MHz + (1 KHz -> 1 MHz).

Is it reasonable for the value "Input frequency range" calculated by the simulator? What does it mean in the divider??

--Tuc

Title: Re: How to perform the PSS+PNOISE for a divider?
Post by pancho_hideboo on Jul 6^th, 2008, 5:44am

Show me netlists about PSS and Pnoise.

Tuc wrote on Jul 2^nd, 2008, 8:41pm:

I want to simulate the phase noise of a divider circuit, however, I'm a little confused with the PNOISE settings:
(i). How to set the output frequency range? The frequency supposed to be get after dividing?

Output frequency of Pnoise is not divided since it is small signal.

Tuc wrote on Jul 2^nd, 2008, 8:41pm:

(ii). The input frequency range? which is calculated by the simulator itself after setting the output frequency range. For example, suppose the divider ratio is 4, and the output frequency after dividing is 100M, I got the following message from the simulation log:
**********************************************************
Periodic Noise Analysis 'pnoise': freq = 100 MHz + (1 KHz -> 1 MHz)
**********************************************************
Input frequency range = 400 MHz + (1 KHz -> 1 MHz).

Is it reasonable for the value "Input frequency range" calculated by the simulator? What does it mean in the divider??

Maybe you set iprobe and reference band in Pnoise. So it is very reasonable as input frequency.
You don't have to set iprobe and reference band in your case.

You can observe noise at freq=N*PSSfund+/-(1kHz~1MHz) with setting sweeptype=relative relharmnum=N in Pnoise.

http://www.designers-guide.org/Forum/YaBB.pl?num=1211952319/3#3

Title: Re: How to perform the PSS+PNOISE for a divider?
Post by Tuc on Jul 6^th, 2008, 7:02pm

Thank you very much Pancho, you're right.

-- Tuc