+ Post New Thread
Results 1 to 12 of 12
  1. #1
    Advanced Member level 5
    Points: 16,713, Level: 31
    pancho_hideboo's Avatar
    Join Date
    Oct 2006
    Location
    Real Homeless
    Posts
    2,566
    Helped
    685 / 685
    Points
    16,713
    Level
    31

    Difference of S-parameters between Cadence Spectre and Keysight ADSsim

    Calculation method of S-parameters is different between Cadence Spectre and Keysight ADSsim.

    Cadence Spectre evaluates Y-parameters first internally.
    Then it converts Y-parameters to S-parameters using reference impedance values.

    Some simulator has option to choose Y or Z parameters.

    On the other hand, Keysigh ADSsim does not use Y or Z parameters to calculate S-parameters.
    Keysigh ADSsim calculate S-parameters directly by power wave formulation.
    Power wave is defined by voltage, current an reference impedance.

    Assume 2-port DUT where Y-parameters don't exist.
    For example, shunt element.

    Cadence Spectre can not give S-parameters.
    Keysigh ADSsim can give S-parameters.
    Last edited by pancho_hideboo; 27th July 2019 at 18:19.

  2. #2
    Advanced Member level 5
    Points: 30,261, Level: 42
    BigBoss's Avatar
    Join Date
    Nov 2001
    Location
    Turkey
    Posts
    4,426
    Helped
    1335 / 1335
    Points
    30,261
    Level
    42

    Re: Difference of S-parameters between Cadence Spectre and Keysight ADSsim

    I don't think so, otherwise it would be great shame for Cadence.
    Which version of spectre do you use but it computes s-parameters of an shunt inductor.
    Click image for larger version. 

Name:	shunt_inductor.png 
Views:	7 
Size:	3.7 KB 
ID:	154610Click image for larger version. 

Name:	smith_shunt.png 
Views:	8 
Size:	162.2 KB 
ID:	154611



    •   AltAdvertisement

        
       

  3. #3
    Advanced Member level 5
    Points: 16,713, Level: 31
    pancho_hideboo's Avatar
    Join Date
    Oct 2006
    Location
    Real Homeless
    Posts
    2,566
    Helped
    685 / 685
    Points
    16,713
    Level
    31

    Re: Difference of S-parameters between Cadence Spectre and Keysight ADSsim

    Quote Originally Posted by BigBoss View Post
    I don't think so, otherwise it would be great shame for Cadence.
    Which version of spectre do you use but it computes s-parameters of an shunt inductor.
    Click image for larger version. 

Name:	shunt_inductor.png 
Views:	7 
Size:	3.7 KB 
ID:	154610Click image for larger version. 

Name:	smith_shunt.png 
Views:	8 
Size:	162.2 KB 
ID:	154611
    How about series element which does not have Z-parameters.



  4. #4
    Advanced Member level 5
    Points: 30,261, Level: 42
    BigBoss's Avatar
    Join Date
    Nov 2001
    Location
    Turkey
    Posts
    4,426
    Helped
    1335 / 1335
    Points
    30,261
    Level
    42

    Re: Difference of S-parameters between Cadence Spectre and Keysight ADSsim

    It's as expected..
    Click image for larger version. 

Name:	smith_series.png 
Views:	3 
Size:	159.0 KB 
ID:	154614



    •   AltAdvertisement

        
       

  5. #5
    Advanced Member level 5
    Points: 16,713, Level: 31
    pancho_hideboo's Avatar
    Join Date
    Oct 2006
    Location
    Real Homeless
    Posts
    2,566
    Helped
    685 / 685
    Points
    16,713
    Level
    31

    Re: Difference of S-parameters between Cadence Spectre and Keysight ADSsim

    Quote Originally Posted by BigBoss View Post
    I don't think so,
    otherwise it would be great shame for Cadence.
    This issue was filed as PCR(Product Change Request)-464911
    "Systems which does not have a valid Y matrix give arithmetic exception"

    Quote Originally Posted by BigBoss View Post
    Which version of spectre do you use
    but it computes s-parameters of an shunt inductor.
    Thanks for confirming.

    I also confirmed.
    Now this issue has been fixed in Cadence Spectre.

    "sp_shunt.scs"
    Code:
    simulator lang=spectre
    global 0
    
    PORT1 (Vin 0) port r=50 num=1 type=dc mag=1
    PORT2 (Vin 0) port r=50 num=2 type=dc
    
    Rx (Vin 0) resistor r=50
    //Rx (Vin 0) resistor r=50/2/(sqrt(2)-1)
    
    heppoko options reltol=1e-5 vabstol=3e-8 iabstol=1e-13 temp=16.85 \
        tnom=27 scalem=1.0 scale=1.0 gmin=1e-12 rforce=1 maxnotes=5 maxwarns=5 \
        digits=5 cols=80 pivrel=1e-3 ckptclock=1800 \
        sensfile="../psf/sens.output" rawfmt=psfascii 
    
    aho noise values=[100M] annotate=status oprobe=PORT2 iprobe=PORT1
    
    boke sp values=[100M] annotate=status donoise=yes oprobe=PORT2 iprobe=PORT1  
    
    kasu ac values=[100M] annotate=status
    
    hyottoko options save=allpub
    "boke.sp"
    Code:
    HEADER
    "PSFversion" "1.00"
    "BINPSF creation time" "1564453319"
    "simulator" "spectre"
    "version" "17.1.0.307.isr6"
    "date" "11:21:59 AM, Tue Jul 30, 2019"
    "design" "(no title)"
    "analysis type" "sp"
    "analysis name" "boke"
    "analysis description" "S-Parameter Analysis `boke': freq = 100 MHz"
    "xVecSorted" "unknown"
    "tolerance.relative" 1.00000e-05
    "mode" "ss"
    "number of ports" 2
    "PORT2:r" 50.0000
    "PORT2:num" 2
    "PORT2:units" "Ohm"
    "PORT1:r" 50.0000
    "PORT1:num" 1
    "PORT1:units" "Ohm"
    TYPE
    "sweep" FLOAT DOUBLE PROP(
    "key" "sweep"
    )
    "S-Param" COMPLEX DOUBLE PROP(
    "key" "SP"
    )
    SWEEP
    "freq" "sweep" PROP(
    "sweep_direction" 0
    "units" "Hz"
    )
    TRACE
    "s22" "S-Param"
    "s12" "S-Param"
    "s21" "S-Param"
    "s11" "S-Param"
    "cy22" "S-Param"
    "cy12" "S-Param"
    "cy21" "S-Param"
    "cy11" "S-Param"
    VALUE
    "freq" 1.00000e+08
    "s22" (-0.333333 0.00000)
    "s12" (0.666667 0.00000)
    "s21" (0.666667 0.00000)
    "s11" (-0.333333 0.00000)
    "cy22" (0.0200000 0.00000)
    "cy12" (0.00000 0.00000)
    "cy21" (0.00000 0.00000)
    "cy11" (0.00000 0.00000)
    END
    Last edited by pancho_hideboo; 4th August 2019 at 09:26.



    •   AltAdvertisement

        
       

  6. #6
    Advanced Member level 5
    Points: 13,978, Level: 28

    Join Date
    Apr 2014
    Posts
    2,181
    Helped
    876 / 876
    Points
    13,978
    Level
    28

    Re: Difference of S-parameters between Cadence Spectre and Keysight ADSsim

    That is why it is important to specify software version when discussing such issues. "Now" is not a useful specification.



  7. #7
    Advanced Member level 5
    Points: 16,713, Level: 31
    pancho_hideboo's Avatar
    Join Date
    Oct 2006
    Location
    Real Homeless
    Posts
    2,566
    Helped
    685 / 685
    Points
    16,713
    Level
    31

    Re: Difference of S-parameters between Cadence Spectre and Keysight ADSsim

    Quote Originally Posted by volker@muehlhaus View Post
    "Now" is not a useful specification.
    See simulation result.
    You can see version which I use.

    However I don’t know in which version this issue was fixed.



  8. #8
    Advanced Member level 5
    Points: 30,261, Level: 42
    BigBoss's Avatar
    Join Date
    Nov 2001
    Location
    Turkey
    Posts
    4,426
    Helped
    1335 / 1335
    Points
    30,261
    Level
    42

    Re: Difference of S-parameters between Cadence Spectre and Keysight ADSsim

    I'm using Spectre 17.10.627 and it seems working..
    But I personally don't like Spectre in RF simulation.You can even not attribute the frequency on Smith Chart to see impedance/admittance at particular frequency..Since 20 years..
    My favorite one is Keysight GoldenGate. It's marvelous..



  9. #9
    Advanced Member level 5
    Points: 16,713, Level: 31
    pancho_hideboo's Avatar
    Join Date
    Oct 2006
    Location
    Real Homeless
    Posts
    2,566
    Helped
    685 / 685
    Points
    16,713
    Level
    31

    Re: Difference of S-parameters between Cadence Spectre and Keysight ADSsim

    Quote Originally Posted by BigBoss View Post
    You can even not attribute the frequency on Smith Chart to see impedance/admittance at particular frequency..Since 20 years..
    Right.
    However this is not issue of Cadence Spectre.
    This issue is for Cadence ViVA.

    Simulation performance of current Cadence Spectre is fairly good even for multi-tone HB Analysis.

    http://www.designers-guide.org/Forum...1170364605/2#2
    https://designers-guide.org/forum/Ya...num=1205223090
    https://designers-guide.org/forum/Ya...num=1162921214


    Quote Originally Posted by BigBoss View Post
    My favorite one is Keysight GoldenGate.
    It's marvelous..
    It is very amazing.
    I think no one use Keysight GoldenGate and even Keysight almost abandon promotion of GoldenGate anymore.
    Keysight GoldenGate is almost EOL.

    https://designers-guide.org/forum/Ya...m=1268404959#7



    •   AltAdvertisement

        
       

  10. #10
    Advanced Member level 5
    Points: 30,261, Level: 42
    BigBoss's Avatar
    Join Date
    Nov 2001
    Location
    Turkey
    Posts
    4,426
    Helped
    1335 / 1335
    Points
    30,261
    Level
    42

    Re: Difference of S-parameters between Cadence Spectre and Keysight ADSsim

    Quote Originally Posted by pancho_hideboo View Post
    It is very amazing.
    I think no one use Keysight GoldenGate and even Keysight almost abandon promotion of GoldenGate anymore.
    Keysight GoldenGate is almost EOL.
    No, Goldengate is still promoted..
    https://www.keysight.com/en/pd-29980...6&cc=US&lc=eng

    This version will be compatible with ADS2020 and IC6.1.8.



  11. #11
    Advanced Member level 5
    Points: 16,713, Level: 31
    pancho_hideboo's Avatar
    Join Date
    Oct 2006
    Location
    Real Homeless
    Posts
    2,566
    Helped
    685 / 685
    Points
    16,713
    Level
    31

    Re: Difference of S-parameters between Cadence Spectre and Keysight ADSsim

    Quote Originally Posted by BigBoss View Post
    No, Goldengate is still promoted..
    There is no thread about Goldengate in this forum.

    There is no reference of Goldengate in foundary document.

    I foresee EOL of Goldengate in near future.



  12. #12
    Advanced Member level 5
    Points: 13,978, Level: 28

    Join Date
    Apr 2014
    Posts
    2,181
    Helped
    876 / 876
    Points
    13,978
    Level
    28

    Re: Difference of S-parameters between Cadence Spectre and Keysight ADSsim

    Quote Originally Posted by pancho_hideboo View Post
    There is no thread about Goldengate in this forum.
    I often think this forum is most popular among the lazy students, people trying to find someome to solve their homework. There's few power users here .. not exactly the community to discuss advanced EDA stuff.



--[[ ]]--