Home > Community > Forums > RF Design > VCO: PSS and pnoise analysis and Numerical Errors

Email

* Required Fields

Recipients email * (separate multiple addresses with commas)

Your name *

Your email *

Message *

Contact Us

* Required Fields
First Name *

Last Name *

Email *

Company / Institution *

Comments: *

 VCO: PSS and pnoise analysis and Numerical Errors 

Last post Wed, Jan 22 2014 9:43 AM by Tawna. 1 replies.
Started by rsrk 22 Jan 2014 03:49 AM. Topic has 1 replies and 3633 views
Page 1 of 1 (2 items)
Sort Posts:
  • Wed, Jan 22 2014 3:49 AM

    • rsrk
    • Not Ranked
    • Joined on Thu, Feb 10 2011
    • Posts 9
    • Points 150
    VCO: PSS and pnoise analysis and Numerical Errors Reply

    Hello,

       I am Sivaramakrishna. My query is about the numerical/simulation errors in pnoise/pss analysis of VCO.

       I am designing a (CMOS LC-) VCO and Interesting I am getting different phase-noise for the same circuit with with same settings, such as initial conditions, and integration methods(it was suggested that I need to use *trap* integration method in-order to get correct results).

       Its varying around 1-to-2 dBc. I feel that this variation is significant as it is in log scale.

       The only way I can, at least to the best of my knowledge, see if the numerical/simulation noise is playing any role. Could someone shed light on it.

    Thanks and Regards

    Sivaramakrishna 

     

        

    • Post Points: 20
  • Wed, Jan 22 2014 9:43 AM

    • Tawna
    • Top 25 Contributor
    • Joined on Thu, Jul 10 2008
    • Snohomish, WA
    • Posts 212
    • Points 5,625
    Re: VCO: PSS and pnoise analysis and Numerical Errors Reply

    Hi Sivaramakrishna,

     If this is a strongly nonlinear circuit (e.g. ring oscillator), then pss-shooting is appropriate.  Otherwise, I would use hb (harmonic balance). 

    Please check out your setup - very important to get correct results.   In my blog:

    SpectreRF Tutorials and Appnotes... Shhhh... We Have a NEW Best Kept Secret!

    I mention the new SpectreRF design workshops, which include  Simulating Oscillators:   LC and Ring Oscillators.

    The workshops take you through step by step the best way to set up your oscillator to get accurate results.  There is also a design database in the hierarchy.  The setup instructions are in Appendix A of the MMSIM12.1.1 or 13.1 SpectreRF User Guide.

    best regards,

    Tawna

    Best regards, Tawna Wilsey Staff Support AE, Global Customer Support Cadence Design Systems, Inc.
    • Post Points: 5
Page 1 of 1 (2 items)
Sort Posts:
Started by rsrk at 22 Jan 2014 03:49 AM. Topic has 1 replies.