ADS S-parameter extraction: port error

[SolidRaven]

Before you start shouting at me that this is easy: I was "given" ADS for a college project. Though at this point I would rather call it torture by ADS. Would make a fairly good Halloween movie I imagine. But to get back to the original subject. Nobody really seems to know how to work with this program as they only bought it for somebody's thesis not too long ago. Since this person has left there isn't really anybody who's actually able to help me with this. They also refuse to give me the account information to login on the Agilent website cause the account is used for other things as well. So I don't have access to the support or the probably extensive online manual/tutorial collection. Needless to say I've been having some headaches, figured out quite a lot of things already but I'm stuck on this one.

The task is fairly simple at first sight: Extract the S-parameters of a PCB trace and extract the impedance values in function of the frequency. Sadly ADS seems to think my pins aren't actually hooked up to the trace.

To guide you through what I've been doing step-by-step:
1) Place two SMD capacitors.
2) Hook them up using a trace. (This forms the concentric shield needed in the design) (layer cond1)
**broken link removed**

3) Draw the inner loop but leave a small gap where it's supposed to be hooked up. (layer cond1)
**broken link removed**

4) Place port pins on the layer cond1:
**broken link removed**

5) EM simulation: FEM doesn't work cause there is no ground, Momentum Microwave seems a bit overkill for something designed to operate at 50 MHz so I go for Momentum RF. There are no warnings at this point so I assume everything is ok. I setup a sweep from 0 to 100 MHz with 200 points and hit simulate.

As far as I'm aware this is the normal way to do S-parameter extraction for a structure in ADS. A few seconds later an error pops up:

Analysis "Solve" (M121021114909) of design coildesign_lib:surface_coil:layout failed.

The simulation log states this:

Simulation Mode: RF
Substrate valid
Using the minimal snap distance of 0.0004 mm
(4 layout resolution points) for layout healing.
--- WARNING -------------------------------------------------------------------

Point pin P1 is outside the simulation boundary and will be ignored.

-------------------------------------------------------------------------------
--- WARNING -------------------------------------------------------------------

Point pin P2 is outside the simulation boundary and will be ignored.

-------------------------------------------------------------------------------
--- WARNING -------------------------------------------------------------------

The port setup needed to be corrected:
Nonexistent pin "P1" has been removed from port
"P1".

-------------------------------------------------------------------------------
--- WARNING -------------------------------------------------------------------

The port setup needed to be corrected:
Nonexistent pin "P2" has been removed from port
"P2".

-------------------------------------------------------------------------------
--- WARNING -------------------------------------------------------------------

The port setup needed to be corrected:
Ports "P1" and "P2" have been removed because
they have no positive pins.

-------------------------------------------------------------------------------
--- ERROR ---------------------------------------------------------------------

The port/pin assignment has been changed. Review
the port setup and try again.

-------------------------------------------------------------------------------

Could somebody please help me with this one?

 

[volker_muehlhaus]

Is your software under Agilent support contract? They have some really good support guys in Belgium & Netherlands.

My best guess as a non-Momentum user is that the ports P1/P2 for the SMD are invalid because there is no ground below, as you mentioned. Every port needs to have signal (+) and ground (-). In your case, without a ground below, Momentum does not know where to put the ground reference for these ports. My best guess is that these ports must be assigned as P1(+)/P1(-) rather than P1/P2. There is a ports dialog for EM where you can assign the two pins to be (+) and (-) for one EM port.

 

[SolidRaven]

I wish I knew, I'll ask tomorrow. But I fear not (considering they don't even want to give me the login for the online help).

 

[volker_muehlhaus]

Ok, then have a look at what I added above, and also at the EM Ports topic in the online help. I think that (+)/(-) ports might be the solution to your problem.

 

[SolidRaven]

Ok, then have a look at what I added above, and also at the EM Ports topic in the online help. I think that (+)/(-) ports might be the solution to your problem.

Thank you! I'll have a look.

Edit: Doesn't seem to help, I also tried to add a bounding box cause it keeps saying "outside the simulation boundary and will be ignored.". To no avail.

Edit 2: I recreated the substrate and now it works all of a sudden. I guess the substrate defined the boundary box incorrectly.