In HFSS terminal mode, the setting of the reference ground depends on the characteristics and requirements of the circuit.
Generally, the reference ground is set to the lowest potential ground point or the larger metal plane in the circuit. This can effectively reduce the noise and interference of the signal, and provide a stable working environment.
Depending on the specific design and requirements, the setting of the reference site may require more detailed consideration and optimization in terms of circuit layout and layering.
There is a perfect E boundary in the boundary condition. There is an infinite number of options below