I have a layout structure that implements GSG pads for transistor characterization.
The GSG pad is connected to a co-planar transmission line that eventually connects to the device. Thus, I defined the Momentum ports as explicit ports where the Signal pad is the positive terminal of the port and the 2 ground pads are the negative terminals of the port. When I run the simulation with the active device the DC operating point is not valid. Only when I set the Momentum ports to implicit i.e. single-ended and referencing the global ground do I get a valid DC solution. Unfortunately this is not the correct way to represent the layout and the EM problem and I wonder if anyone knows how can I use explicit ports and still get a valid DC solution.