HFSS15: Differential Admittance and Impedance Matrices

The terminal admittance (Y) and impedance (Z) matrices discussed in the previous topics in the Technical Notes relate single-ended voltages and currents as i = Yv and v = Zi, respectively. If you defined differential voltages and currents e and u, equations (3) can be used to derive new Y and Z matrices that relate differential quantities.

For example, if i = Yv , then substituting equations (3) yields

Q^-Tu = YQe.

Solving for u yields

u = Q^TYQe

and the matrix Y^’ relating differential quantities e and u is defined by

A similar procedure applies to the terminal Z matrix.