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 evaluating the output spectrum 

Last post Tue, Sep 20 2011 2:34 PM by arapsc. 4 replies.
Started by whlinfei 12 Jun 2011 11:50 PM. Topic has 4 replies and 5926 views
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  • Sun, Jun 12 2011 11:50 PM

    • whlinfei
    • Top 500 Contributor
    • Joined on Sun, Mar 15 2009
    • Posts 24
    • Points 435
    evaluating the output spectrum Reply

    Hi,

     I have finished transient simulation on my transmitter, after three days.

    I can now load  the output waveform in the plot. I hope that I can extract the data and use matlab to get the power spectral density plot.

    But everytime I try to load the data into a table, which is supposed to be quite large, the loading takes forever and never gave me the final  table.

    Is there any  way to circumvent this problem and analyze the final spectrum ?

     

    Thanks.

    whlinfei

    • Post Points: 20
  • Mon, Jun 13 2011 1:32 AM

    Re: evaluating the output spectrum Reply
    Two quick ideas. Either use the psd function in the calculator, or use the Spectre Toolbox for Matlab which allows you to read the simulation results directly into Matlab.

    This is covered in the documentation - search for Matlab.

    Andrew
    • Post Points: 20
  • Wed, Jun 15 2011 4:10 AM

    • whlinfei
    • Top 500 Contributor
    • Joined on Sun, Mar 15 2009
    • Posts 24
    • Points 435
    Re: evaluating the output spectrum Reply
    Hi Andrew, Thank you for the reply. Unfortunately the cadence version I am using seems having some trouble using psd function and it does not include the matlab function you mentioned. I tried ocnprint function. It can work. But the printing time is almost as long as the simulation time. Is there anyway I can speed up ocnprint ?
    • Post Points: 20
  • Wed, Jul 27 2011 2:58 AM

    Re: evaluating the output spectrum Reply

    The reason why I've not responded to this sooner (other than being rather busy) is because there simply is not enough information to go on. You didn't say what version of the IC tools or spectre that  you're using. You didn't say what the expressions you were using were. You didn't give the ocnPrint statement that you used. You didn't give any information as to how many points there were - quite simply, any response would have to be based on so much guess work, that it would be of little value.

    Remember that everyone (including the Cadence folk) on this forum are responding here on a voluntary basis (it's a community forum, rather than a support site), and so the more information you provide, the better your chances of getting a prompt answer.

    Regards,

    Andrew.

    • Post Points: 20
  • Tue, Sep 20 2011 2:34 PM

    • arapsc
    • Not Ranked
    • Joined on Mon, Sep 12 2011
    • Federal Way, WA
    • Posts 8
    • Points 100
    Re: evaluating the output spectrum Reply
    I use the following method for PSD analysis in matlab. I plot the signal in wavescan (ade graphics tool) and use the menu Trace/Save to matlab format (options pop up). Then you can post process this file in matlab (remember to avoid the first row in the file). If sampling time is not constant, I sample the waveform using calculator to plot another waveform which I then post process.
    • Post Points: 5
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Started by whlinfei at 12 Jun 2011 11:50 PM. Topic has 4 replies.