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Measurements >> Phase Noise and Jitter Measurements >> To find PSD
https://designers-guide.org/forum/YaBB.pl?num=1082297670

Message started by sachinkr on Apr 18^th, 2004, 7:14am

Title: To find PSD
Post by sachinkr on Apr 18^th, 2004, 7:14am

Hi,
I used paper "Modelling jitter in PLL based frequency Synthesizer" to find PSD . For this i refer the MATLAB script given in this paper. In that it is mentioned time points are necessary to give in "load perios.m" file. I simaulate frequency synthesizer (transistor level)using SpectreRF and then i gave the time points of VCO sinsoidal output wavefrom. Is this ok or not ? I am not sure about this. Can anybody help me about this?
Waiting for reply.

Title: Re: To find PSD
Post by Jitter Man on Apr 18^th, 2004, 8:50am

The file "periods.m" contains the length of each period of the output signal. There is one number per period. It is generated from the VCO model in Listing 16 on page 41 of "Predicting the phase noise and jitter of PLL-based frequency synthesizers ", which can be found at www.designers-guide.com/Analysis.

[glb]Jitter Man[/glb]

Title: Re: To find PSD
Post by sachinkr on May 13^th, 2004, 11:46pm

Sir,
I simulated PLL frequency synthesizer operating at 900 MHz and then i took period length of each sinusoidal signal to plot PSD. But you just tell me how many period length i have to take? right now i took 20. A

Title: Re: To find PSD
Post by sachinkr on May 13^th, 2004, 11:58pm

Sir,
I simulated PLL frequency synthesizer in RF Spectre. To plot PSD i took the length of output periods of PLL output when PLL lock. Is it ok or not? Also i don't know how many length of periods I have to take , right now I took 20 . Please tell me detals. Waiting for your reply.
Thank you.
sachin