Finite Ground and Defected Ground Structures (DGS) in ADS (Momentum)

Simulating Finite Ground and Defected Ground Structure in ADS using Momentum EM solver is very commonly asked question to me.

Here is one short note explaining the setup which can be easily used by designers.

Kindly let me know if you would like to obtain the ADS workspace in which these simulations are performed.

Happy Designing….!!!

Momentum-FiniteGnd and DGS.pdf


8 thoughts on “Finite Ground and Defected Ground Structures (DGS) in ADS (Momentum)

  1. Hi Theepak, You are right keeping P3 away from P1 will add little bit of parasitics and I have done that to show both of the ports clearly. In ideal situations you should keep them in same Z-orientation but incase where you do not have ground plane right below the signal line, you can select the closest possible conductor on finite ground plane and under no circumstances it should be more than half-wavelength. Hope this helps


  2. Good one Anurag. I have two questions. If I put the port location same as Theepak Shoundr said. The S-parameter response is distorted, especially on high frequencies, let’s say above 5GHz. Moreover, I would like to ask that is it possible to use the finite ground plane for momentum optimization? If yes how can we define parameter value to DGS and ground plane?


    1. Hello Mohammad,
      The thread which you mentioned discusses about finite substrate size. Momentum is MoM based solver which uses infinitely long planar substrate and you can use FEM in ADS if you wish to simulate that. The post which I did is for finite ground plane that is limited ground size and finite conductivity which is different than finite substrate.


      1. Hi Anurag,
        I’m currently evaluating Momentum in ADS 2016. How do I obtain the workspace used in “Understanding Finite Ground and Defected Ground Structures in Momentum”? Excellent article for the evaluation.


      2. Hello Randy,
        Unfortunately, I didn’t retain the copy of ADS workspace for this exercise so you might need to recreate it yourself using the information provided in the note.


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