Problem of phase noise file used in vsource/port

What is the content of the phase noise file?

Andrew.

Hi Andrew,

Glad to see you again.

The phase noise file is from a VCO PSS+Pnoise simulation and is saved as ".in.spectre" format.

For the "V^2/Hz" unit, the content of the phase noise file is as follows:

1000 6.747142755659377e-06
1258.92541217804 3.518040402278265e-06
1584.89319229126 1.854332386171024e-06
1995.262314796448 9.892971175160288e-07
2511.886431694031 5.34804244944805e-07
3162.277660369873 2.931942682960038e-07
3981.071705818176 1.63088135943388e-07
5011.872336387634 9.205257092193872e-08
6309.573444366455 5.270578632922997e-08
7943.282347679138 3.059061726622126e-08
10000 1.798010746864969e-08

For the "dBc/Hz" unit, the content of the phase noise file is as follows:

1000 -50.21286053284982
1258.92541217804 -53.04004042134945
1584.89319229126 -55.82002572244907
1995.262314796448 -58.54736153907031
2511.886431694031 -61.21730349029586
3162.277660369873 -63.82624661111784
3981.071705818176 -66.37209203836673
5011.872336387634 -68.85447798999996
6309.573444366455 -71.27482406633345
7943.282347679138 -73.63617855114491
10000 -75.94290320474452

Xiang

Dear christon,

Did you review the procedure for including the phase noise expressed in dBc/Hz in a port in article at URL:

https://support.cadence.com/apex/ArticleAttachmentPortal?id=a1Od0000000tiraEAA&pageName=ArticleContent

I was not sure if you set the type as sin and included the frequency information and amplitude in the dialog box shown in this article. In addition, the article notes the units should be in dBc - not the units you noted as "For the "dBc/Hz" unit, the content of the phase noise file is as follows:"

Shawn

Dear Shawn,

Unfortunately I do not have the Host Id or Ref Key to see the link you provided.

Since I put the phase noise file into the vsource/port for a PLL phase domain simulation, the source type I set is dc.

Sorry, it is dBc instead of dBc/Hz in the vsource/port noise type option. The values are correct.

Xiang

Dear Xiang,

christon said:

Unfortunately I do not have the Host Id or Ref Key to see the link you provided.

I have attached a Portable Document Formatted version of the URL I provided. Please note the comment about the source type in the article. I hope this helps!

how_to_specify_phase_noise_as_an_instance_parameter_in_spectre_sources.pdf

Shawn

Dear Shawn,

Thank you. But I am doing the phase domain simulation (so that it can be very fast), so I need to set the source type to be "dc".

The problem is that, when I manually key all frequency/dBc points into the vsource/port, it works; but when I try to use the file, it shows the error.

Xiang

Hi Xiang,

The SSB Phase Noise option only makes sense if the source type is set to sine because it is modelled as pure PM noise and so needs the time varying source in an RF analysis. So it's not suitable if you're just doing a linear time-invariant noise analysis. I would suggest that you look at the PLL Workshop under Rapid Adoption Kits on support.cadence.com but you said you don't have access (if I remember rightly, this covers strategies for analysing noise across a PLL using a variety of techniques, including phase domain modelling).

Regards,

Andrew,

Hi Andrew,

With the help of our CAD team and Cadence, I can access the online support now. I find the PLL phase domain simulation in PLL workshop. Thank you very much.

Best regards,

Xiang

Hi Andrew,

With the help of our CAD team and Cadence, I can access the online support now. I find the PLL phase domain simulation in PLL workshop. Thank you very much.

Best regards,

Xiang