HFSS15: Terminals and Modes

A terminal is assigned on a conductor in contact with the port. A port with n+1 distinct conductors that do not touch each other, will support n terminals where the remaining conductor is the local reference ground. The solver generates an error if the number of terminals exceeds n conductors.

The solver uses as many modes as terminals. These modes are not eigen modes and sometimes referred to as terminal modes. The solver computes terminal modes where all the terminal modes are a superposition of eigen modes such that the S-parameters computed by the solver constitute the corresponding terminal S-Matrix instead of the eigen S-Matrix.

For terminal projects we will deal only with transmission lines and assume that the currents and voltages correspond to quasi-TEM modes. The number of terminal modes is dictated by the number of conductors on the port in the project. Proper port definitions should ensure that no higher order propagating modes exist in the transmission lines.