+ Post New Thread
Results 1 to 7 of 7
  1. #1
    Advanced Member level 1
    Points: 4,779, Level: 16

    Join Date
    Jul 2005
    Location
    Oakland
    Posts
    460
    Helped
    63 / 63
    Points
    4,779
    Level
    16

    [ADS] Filter simulation with spiral inductor

    im simulating a filter in ADS with two spiral inductors (coil) at the layer 3 and layer 4.

    however, my layer 1 has RF traces and components, layer 2 is GND, layer 3 is a coil and layer 4 is another coil. i selected GND layer as slot. the rest of the layers are strip layers with finite copper thickness (not sheet metal). However, im not getting correlation between layout simulation and circuit simulation with "TL-multilayer".

    i have a feeling that ADS not simulating inner layers well even if i define it as strip layer with finite copper thickness. Please let me know if my analysis is correct.

    •   AltAdvertisement

        
       

  2. #2
    Advanced Member level 5
    Points: 29,511, Level: 41
    BigBoss's Avatar
    Join Date
    Nov 2001
    Location
    Turkey
    Posts
    4,289
    Helped
    1298 / 1298
    Points
    29,511
    Level
    41

    Re: [ADS] Filter simulation with spiral inductor

    Why did you select GND as slot ? Can you post the substrate illustration picture here ??



    •   AltAdvertisement

        
       

  3. #3
    Advanced Member level 5
    Points: 13,403, Level: 27

    Join Date
    Apr 2014
    Posts
    2,082
    Helped
    844 / 844
    Points
    13,403
    Level
    27

    Re: [ADS] Filter simulation with spiral inductor

    Quote Originally Posted by pragash View Post
    and circuit simulation with "TL-multilayer"
    Can you show a screenshot of your schematic model? Schematic models couple to each other only through the circuit nodes, I wonder if that is realistic for your layout.


    1 members found this post helpful.

    •   AltAdvertisement

        
       

  4. #4
    Advanced Member level 1
    Points: 4,779, Level: 16

    Join Date
    Jul 2005
    Location
    Oakland
    Posts
    460
    Helped
    63 / 63
    Points
    4,779
    Level
    16

    Re: [ADS] Filter simulation with spiral inductor

    Quote Originally Posted by BigBoss View Post
    Why did you select GND as slot ? Can you post the substrate illustration picture here ??
    the strip will consume a substantial amount of simulation time. converting GND layer to slot save simulation time without sacrificing the accuracy.

    - - - Updated - - -

    Quote Originally Posted by volker@muehlhaus View Post
    Can you show a screenshot of your schematic model? Schematic models couple to each other only through the circuit nodes, I wonder if that is realistic for your layout.
    Click image for larger version. 

Name:	schematic model.png 
Views:	5 
Size:	287.2 KB 
ID:	151113

    attached here. how do check circuit nodes?



  5. #5
    Advanced Member level 5
    Points: 13,403, Level: 27

    Join Date
    Apr 2014
    Posts
    2,082
    Helped
    844 / 844
    Points
    13,403
    Level
    27

    Re: [ADS] Filter simulation with spiral inductor

    Quote Originally Posted by pragash View Post
    attached here. how do check circuit nodes?
    I meant the schematic models (circuit simulation). You write that it doesn't agree to EM, so I wonder how you modelled this in circuit simulation (what models and values).

    One possibly related issue: From what I remember, you had used MSUB parameters with almost perfect conductivity in a previous discussion.



    •   AltAdvertisement

        
       

  6. #6
    Advanced Member level 5
    Points: 33,632, Level: 44

    Join Date
    Oct 2001
    Posts
    4,803
    Helped
    1420 / 1420
    Points
    33,632
    Level
    44

    Re: [ADS] Filter simulation with spiral inductor

    Any particular reason why did you use at one end of the inductor VIAS almost 3 times bigger than the VIAS on the other end?
    Because they are in series, the DC current through all of them is the same, so will not help much (for this reason) to make bigger only some of them.



  7. #7
    Advanced Member level 1
    Points: 4,779, Level: 16

    Join Date
    Jul 2005
    Location
    Oakland
    Posts
    460
    Helped
    63 / 63
    Points
    4,779
    Level
    16

    Re: [ADS] Filter simulation with spiral inductor

    Quote Originally Posted by vfone View Post
    Any particular reason why did you use at one end of the inductor VIAS almost 3 times bigger than the VIAS on the other end?
    Because they are in series, the DC current through all of them is the same, so will not help much (for this reason) to make bigger only some of them.
    i used bigger ground vias to not to introduce additional inductance. i couldn't make the other side inductor bigger due to RF trace constraint.



--[[ ]]--