The ideal symmetrical transformer, as shown in fig. 9.3, is determined by the following equations which introduce two more unknowns in the MNA matrix.
(9.30) |
The new unknown variables and must be considered by the six remaining simple equations.
(9.32) |
(9.33) |
The matrix representation needs to be augmented by two more new rows and their corresponding columns. For DC and AC simulation it is:
(9.34) |
Using the port numbers depicted in fig. 9.3, the scattering parameters of an ideal, symmetrical transformer with voltage transformation ratio (number of turns) and , respectively, writes as follows.
(9.35) |
(9.36) | |||
(9.37) | |||
(9.38) |
(9.39) |
(9.40) |
(9.41) |
An ideal symmetrical transformer is noise free.