+ Post New Thread
Results 1 to 7 of 7
  1. #1
    Member level 3
    Points: 1,373, Level: 8

    Join Date
    Feb 2013
    Posts
    65
    Helped
    1 / 1
    Points
    1,373
    Level
    8

    PNoise Analysis of ILO

    Hello,

    I am running PNoise analysis for my Injection-locked oscillator before and after injection. Before injection, it's just a VCO, and in SweepType field, I choose "relative". However, when I inject a signal, "relative" option gets me the same PNoise of the VCO, which is not reasonable. My question is, since ILO is a driven circuit, should Sweeptype be "Absolute" or "default", especially as their results are very reasonable? and what are the difference between the three options?

    Thanks,

    Click image for larger version. 

Name:	Screenshot.png 
Views:	0 
Size:	24.1 KB 
ID:	150017

    •   AltAdvertisment

        
       

  2. #2
    Advanced Member level 5
    Points: 14,423, Level: 28
    pancho_hideboo's Avatar
    Join Date
    Oct 2006
    Location
    Real Homeless
    Posts
    2,171
    Helped
    595 / 595
    Points
    14,423
    Level
    28

    Re: PNoise Analysis of ILO

    See pnoise statement in netlist.
    Also see logfile of spectre.


    1 members found this post helpful.

  3. #3
    Member level 3
    Points: 1,373, Level: 8

    Join Date
    Feb 2013
    Posts
    65
    Helped
    1 / 1
    Points
    1,373
    Level
    8

    Re: PNoise Analysis of ILO

    Quote Originally Posted by pancho_hideboo View Post
    See pnoise statement in netlist.
    Also see logfile of spectre.
    Thank you so much :)

    I have one more question just to make sure I do it right: I inject my circuit with a 5-GHz signal and the o/p is 1GHz. Does it mean Sweeptype is "relative" in this case or still "absolute" as the circuit is actually driven?
    Last edited by Engineer4ever; 19th November 2018 at 20:17.



    •   AltAdvertisment

        
       

  4. #4
    Advanced Member level 5
    Points: 14,423, Level: 28
    pancho_hideboo's Avatar
    Join Date
    Oct 2006
    Location
    Real Homeless
    Posts
    2,171
    Helped
    595 / 595
    Points
    14,423
    Level
    28

    Re: PNoise Analysis of ILO

    Quote Originally Posted by Engineer4ever View Post
    I inject my circuit with a 5-GHz signal and the o/p is 1GHz.
    What do you mean by "o/p" ?

    Quote Originally Posted by Engineer4ever View Post
    Does it mean Sweeptype is "relative" in this case
    or still "absolute" as the circuit is actually driven?
    I can not understand what you want to mean at all.
    However if your analysis is a PSS analysis with fundamental_frequency=1GHz, it is a driven PSS analysis.

    Why do you relay on default setting in Pnoise ?
    Simply set sweeptype as relative or absolute clearly without using default.
    That's all.


    And you can confirm actual sweeptype used for Pnoise in Spectre logfile.
    Surely see logfile of Spectre.
    Last edited by pancho_hideboo; 25th November 2018 at 08:26.


    1 members found this post helpful.

  5. #5
    Member level 3
    Points: 1,373, Level: 8

    Join Date
    Feb 2013
    Posts
    65
    Helped
    1 / 1
    Points
    1,373
    Level
    8

    Re: PNoise Analysis of ILO

    Thanks for your reply.

    What do you mean by "o/p" ?
    By "o/p" I mean the o/p of the ILO. I inject the VCO with a 5-GHz and since it's a 5-stage super-harmonic ILO, its o/p is 1GHz.



    •   AltAdvertisment

        
       

  6. #6
    Advanced Member level 5
    Points: 14,423, Level: 28
    pancho_hideboo's Avatar
    Join Date
    Oct 2006
    Location
    Real Homeless
    Posts
    2,171
    Helped
    595 / 595
    Points
    14,423
    Level
    28

    Re: PNoise Analysis of ILO

    Quote Originally Posted by Engineer4ever View Post
    By "o/p" I mean the o/p of the ILO.
    Do you think it can serve answer ?
    What do you mean by "o/p" ?

    OPen ?
    OPeration ?
    OutPut ?



  7. #7
    Member level 3
    Points: 1,373, Level: 8

    Join Date
    Feb 2013
    Posts
    65
    Helped
    1 / 1
    Points
    1,373
    Level
    8

    Re: PNoise Analysis of ILO

    Quote Originally Posted by pancho_hideboo View Post
    Do you think it can serve answer ?
    What do you mean by "o/p" ?

    OPen ?
    OPeration ?
    OutPut ?

    By o/p I mean output. Apologies if it isn't clear, I always write it like that.



--[[ ]]--