+ Post New Thread
Results 1 to 7 of 7
  1. #1
    Advanced Member level 2
    Points: 3,530, Level: 13

    Join Date
    Feb 2016
    Posts
    680
    Helped
    1 / 1
    Points
    3,530
    Level
    13

    Marchand balun layout

    For this marchand balun schematics in ADS, how to instruct the ADS layout generator to use coil shape (for area saving in IC) ?

    Besides, anyone have any experience with planar layout of marchand balun on PCB ?





    balun schematics







    generated balun layout not in coil shape







    balun layout in coil shape


    •   AltAdvertisement

        
       

  2. #2
    Advanced Member level 5
    Points: 14,284, Level: 28

    Join Date
    Apr 2014
    Posts
    2,239
    Helped
    892 / 892
    Points
    14,284
    Level
    28

    Re: Marchand balun layout

    1) ADS doesn't convert to physical layout (dimension) if your schematic has electrical parameters (impedance).
    2) If your schematic has straight coupled line, that is what you get in layout.
    3) There is no predefined layout element for such interleaved inductors, unfortunately.

    So there is a lot of manual layout work ahead.


    1 members found this post helpful.

    •   AltAdvertisement

        
       

  3. #3
    Advanced Member level 2
    Points: 3,530, Level: 13

    Join Date
    Feb 2016
    Posts
    680
    Helped
    1 / 1
    Points
    3,530
    Level
    13

    Re: Marchand balun layout

    Someone else told me to replace CLIN with 2 Symmetrical Coupled Microstrip Lines (MCP) and then use linecalc to get the correct length and width.

    What do you think about this idea ?



    •   AltAdvertisement

        
       

  4. #4
    Advanced Member level 5
    Points: 14,284, Level: 28

    Join Date
    Apr 2014
    Posts
    2,239
    Helped
    892 / 892
    Points
    14,284
    Level
    28

    Re: Marchand balun layout

    Quote Originally Posted by promach View Post
    Someone else told me to replace CLIN with 2 Symmetrical Coupled Microstrip Lines (MCP) and then use linecalc to get the correct length and width.
    What do you think about this idea ?
    Yes, that's fine, but it will be straight lines.


    1 members found this post helpful.

  5. #5
    Advanced Member level 2
    Points: 3,530, Level: 13

    Join Date
    Feb 2016
    Posts
    680
    Helped
    1 / 1
    Points
    3,530
    Level
    13

    Re: Marchand balun layout

    So there is a lot of manual layout work ahead.
    Yes, I am now trying to replicate planar layout of marchand balun on PCB using SonnetLite instead.

    This book Microstrip Filters for RF Microwave Applications has some good examples (maths theory + implementation) on microstrip filters, but not balun.




    •   AltAdvertisement

        
       

  6. #6
    Advanced Member level 2
    Points: 3,530, Level: 13

    Join Date
    Feb 2016
    Posts
    680
    Helped
    1 / 1
    Points
    3,530
    Level
    13

    Re: Marchand balun layout

    How do we see from the following expressions that even-mode to odd-mode impedance ratio is very important for balun ?




  7. #7
    Advanced Member level 2
    Points: 3,530, Level: 13

    Join Date
    Feb 2016
    Posts
    680
    Helped
    1 / 1
    Points
    3,530
    Level
    13

    Re: Marchand balun layout

    How to derive the expressions involving Ya, Yb, Zoe,Zoo ?

    And why need to increase Zoe/Zoo impedance ratio ?



--[[ ]]--