I am a new user to ADS and running v2011.01. There apparently used to be a Momentum pull down menu in older versions which allowed the user to do extensive PORT edits such as define a port as Single, Internal, Differential, Common Mode, and Ground Reference. In the current version when I add a PIN I have created a PORT which is defined in only 3 ways INPUT, OUTPUT and IN/OUT.
What I want to be able to do is place a PIN/PORT on a metal trace and then allow me to define the return or ground reference instead of letting the tool select this reference (not sure in the current version which return reference it chooses). So, simply define Port 1 on a metal trace on say TOP layer then select a metal structure on the TOP (electrically close), place a Pin/Port but make this a Ground reference and then associate the Port 1 to this ground reference.