problem when generating s parameters using ads 2011.5 momentum

Hello,

Recently our department switched to ads 2011.9. When I tried to use the new version to give me s parameters, it only obtained s11.... no s12, no s22,,no s21..

what happened?

I used the same setting as in my previous proj in ads 2009..i have two loop inductors in free space. each indctor has two terminal and I used one differential port for two terminals.

Thanks for your help in advance.

Do you mean that you have two differential ports?

Hello, Hamid,

I received your personal message. I cannot reply to you because of your personal setting.
For me, I used differential port and hence didn't need to define any ground. If you draw your PGS in slot plane, then the conductive part on that plane is automatically grounded by Momentum. In that case, no need to define ground either.

I do have some questions on some terms in your message.

1) How did you "define ground reference ports for each single port on the PGS"?

2) Which one is the custom GND and which one is the Momentum's GND? I am confused over the terms you mentioned.

Thanks a lot

Hi grot_fire

Thanks for your reply and sorry for my not appropriate settings

Regarding your questions:

1) For transmission line case, imagine that we have our TL on say cond layer. Then there is two way to define ground: first is using infinite GND which is not needed to be defined and indicated by ///GND/// in the layer stack; second way is to make than ///GND/// (which is closed boundary) open boundary and define a FINITE ground layer on say cond2. Then for every single port on cond layer we have to define a "ground reference port" on cond2 layer. In my case PGS was on cond2 layer

2) In the above explanation cond2 will be my costum ground layer for 2nd case and ///GND/// will be Momentum's GND for 1st case.

again thank you for your reply

---------- Post added at 11:22 ---------- Previous post was at 09:23 ----------

The conductive part on slot layer will be treated as perfect conductor, why is that you think that it will be treated as ground. I mean single ports need ground somewhere near them and having only slot layer without ///GND/// (closed boundary of momentum) will not generate reasonable results.

On the other hand PGS is usually on the poly which is way different than perfect conductor

Dear grit-fire

I have created a new thread about my problem, could you please read that post and post a reply in case you know the solution,
Thanks

https://www.edaboard.com/thread228904.html