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# PN function in Visualizaion & Anaysis XL Calculator

Last post Tue, Feb 18 2014 10:50 PM by Andrew Beckett. 4 replies.
 Started by JaeWook 18 Feb 2014 03:34 PM. Topic has 4 replies and 1653 views
• #### Tue, Feb 18 2014 3:34 PM

• JaeWook
• Joined on Tue, Feb 18 2014
• Santa Clara, CA
• Posts 5
• Points 85
PN function in Visualizaion & Anaysis XL Calculator
 Hi,I have a question about the PN function, available in the Calculator. Is an output phase noise spectrum is a signle sideband or a double sideband spectrum?To avoid any confusions, I mean the 'double sideband' by a spectrum 3dB more than the 'single sideband' in magnitude. Thanks for any comment or answers.Jae Wook
• Post Points: 20
• #### Tue, Feb 18 2014 4:01 PM

Re: PN function in Visualizaion & Anaysis XL Calculator
 I suspect it's single sideband, but I'm not sure (I've never used it). It's for analysing transient results, and is defined this way:PN Calculates the transient phase noise of the input waveforms indecibels (dBc/Hz). Phase noise is defined as the power spectraldensity of the absolute jitter of an input waveform.You tagged this post with lots of terms like pss, pnoise etc - so you would not use this function if you're using pnoise. You'd use the pn() or phaseNoise() functions, and these will give you the single sideband phase noise (strictly the output noise in dBc if using "sources"). You'd be better off using "modulated" pnoise and then you can get either from the direct plot form.Regards,Andrew.
• Post Points: 35
• #### Tue, Feb 18 2014 4:56 PM

• JaeWook
• Joined on Tue, Feb 18 2014
• Santa Clara, CA
• Posts 5
• Points 85
Re: PN function in Visualizaion & Anaysis XL Calculator
 Dear Andrew,Thank you for the reply.What I try to do is to make a transient phase noise model of a VCO in veriloga. In order to verify my veriloga model by comparison, I need to run both a pss/pnoise analysis in transistor level and a transient analysis in behavioral level. Then I compare two spectrums from the pnoise and the transient analyses. That is why I care about the PN function as much as other pnoise functions.I appreciate your help again, and if any futher comment or suggestion possible, please let me know. Jae Wook
• Post Points: 5
• #### Tue, Feb 18 2014 6:05 PM

• smlogan
• Joined on Tue, Jun 10 2014
• Posts 105
• Points 1,800
Re: PN function in Visualizaion & Anaysis XL Calculator
 Hi JaeWook,The December 2012 ViVa reference manual describes the pn() function as follows:"Returns a waveform for the transient phase noise of the input waveforms in decibels (dBc/Hz). Phase noise is defined as the power spectral density of the absolute jitter of an inputwaveform."Hence, as Andrew mentions, it is not the classical L(f) function which expresses the single sideband phase noise of a signal. The manual further defines it as:  I hope this helps! Shawn
• Post Points: 20
• #### Tue, Feb 18 2014 10:50 PM

Re: PN function in Visualizaion & Anaysis XL Calculator
 Shawn,The question is about the PN function not the pn function. They are different. The definition you've given is from the PN function (just trying to avoid confusion)Regards, Andrew
• Post Points: 5