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 Clarification regarding AM & PM component simulation in PNOISE (particularly for Oscillator) 

Last post Thu, Jul 11 2013 11:16 AM by Tawna. 4 replies.
Started by RFStuff 05 Jul 2013 08:44 AM. Topic has 4 replies and 844 views
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  • Fri, Jul 5 2013 8:44 AM

    • RFStuff
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    Clarification regarding AM & PM component simulation in PNOISE (particularly for Oscillator) Reply

    Dear All,

    I  simulated a simple LC oscillator noise ( PSS+PNOISE) at the oscillator output ( IC5141, .sub-version  12.1.0.402.isr5).

    I have also saw  the topic "Explain the differences between the 4 noisetype settings for pnoise". But it could not answer what I want.

    I used Shooting Method for PSS. I actually wanted to find the AM Noise & PM noise component separately. For total output noise I used PSS+PNOISE analysis. The noise power in db10 looks ok as it is matching the analysis. And it is a Single Sided PSD.

    I have attached the waveform of it as Total-Noise.png

    However, when I tried to plot AM noise component and PM Noise component separately I faced a really horrible experience. It is really confusing !!

    Could anybody please clarify the following. It will be really helpful not only for me but also for many other designers.

    1:-

    First of all the plot form format in pnoise -source-modulated is very different form.

        a) Power is being plotted in absolute value?   why not in db10 like Pnoise ( is it because of IC5141 )

        b) dBV option is there unlike PNOISE form. Why ?

        c) USB, LSB, AM & PM

         What is USB:-

         is it total noise (AM+PM) in Fcenter + Fif   ?  ( is it Single sided or double sided PSD )

         What is LSB :-

         is it total noise in Fcenter - Fif   ?  ( is it Single sided or double sided PSD )

         What is AM:-

         Is it only AM noise component ?

        is it ( Single-Sided or Double Sided PSD ) As there is dbV I suspect it is all Single Sided PSD )  ?

        is it possible to plot AM Noise in Fcenter + Fif band & Fcenter - Fif band ?

     What is PM:-

      Is it only PM noise component ?

      Is it ( Single-Sided or Double Sided PSD ) ?

      Is it possible to plot AM Noise in Fcenter + Fif band & Fcenter - Fif band ?

    2:-

    When I plotted the AM noise ( I have captured it in the figure as AM-Noise_dBV.png ), It didn't match the analysis in the lower frequncy range.  I plotted in dBV as when I Plotted it gives me -ve value also  below 1MHz ( attached as AM-Noise-Power.png).

    Beyond 10MHz it was matching with analysis. Also I am finding a NOTCH in the AM-PSD why is this ?

    3:- 

    When I plotted the PM noise  ( I have captured it in the figure as PM-Noise_dBV.png ), itis exactly folllowing the total -power as drawn in pnoise analysis but with around 3-dB less

     

     Kind Regards,

        

     


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  • Fri, Jul 5 2013 8:53 AM

    • RFStuff
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    Re: Clarification regarding AM & PM component simulation in PNOISE (particularly for Oscillator) Reply

     AM-Noise_dBV.png is attached here


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  • Fri, Jul 5 2013 8:54 AM

    • RFStuff
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    • Joined on Tue, Feb 5 2013
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    Re: Clarification regarding AM & PM component simulation in PNOISE (particularly for Oscillator) Reply

    AM-Noise_Power..PNG is attached here


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  • Fri, Jul 5 2013 8:58 AM

    • RFStuff
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    • Joined on Tue, Feb 5 2013
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    Re: Clarification regarding AM & PM component simulation in PNOISE (particularly for Oscillator) Reply

     PM-Noise-dBV.png Attached here


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  • Thu, Jul 11 2013 11:16 AM

    • Tawna
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    Re: Clarification regarding AM & PM component simulation in PNOISE (particularly for Oscillator) Reply

    Hi RF Stuff,

     

    This sort of thing should really be addressed by contacting Cadence Customer Support (http://support.cadence.com ) rather than on the forum.  

    I cannot answer these questions at the moment (I have my "day job" to attend to!  <grin>) but I strongly recommend that you look at the MMSIM12.1.1 SpectreRF documentation on Cadence Online Support.  It is really thorough and explains a lot of these terms.

    A link to this is: 

    http://support.cadence.com/wps/mypoc/cos?uri=deeplinkmin:DocumentViewer;src=pubs;q=/spectreRF/spectreRF12.1.1/Chap3.html#hbnoise

    http://support.cadence.com/wps/mypoc/cos?uri=deeplinkmin:DocumentViewer;src=pubs;q=/spectreRF/spectreRF12.1.1/Chap4.html#pnoise

    best regards,

    Tawna

    Best regards, Tawna Wilsey Staff Support AE, Global Customer Support Cadence Design Systems, Inc.
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Started by RFStuff at 05 Jul 2013 08:44 AM. Topic has 4 replies.