Using Port Number Zero for Ground Connections

The Port 0 feature allows you to add connections to ground that are de-embedded during the em simulation. Ports can be assigned a number “0” as shown in the picture below.

This feature allows you to add an ideal short circuit to your circuit in locations other than the analysis box sidewall. In the example above, a boxwall port with a reference plane was used to create an ideal short circuit at the edge of a patterned ground shield. Assigning the port number 0 sets the port to be an ideal short circuit, and the reference plane is used to shift the short circuit to the desired location.

All ports with the number “0” are treated as a normal port during the main part of the EM simulation. These ports are de-embedded in exactly the same manner as all other ports. When the simulation for a particular frequency is completed, em then automatically shorts out all ports with the number 0. This means that the effects of the port are de-embedded without creating extra ports in your S-parameter results.

All port types: box-wall, co-calibrated, via, and delta gap can be set to 0. Multiple ports within a circuit can be set to number 0 just as multiple ports can use the same number as discussed in Ports with Duplicate Numbers.