Traditional representations of magnetic coupling
HF transformers with N windings

Electrical engineers long ago realized that, to translate the galvanic isolation provided by a passive component, they needed a special component: they introduced the perfect transformer ([26] and [27]).

The voltages entering and leaving this element (figure 5) are in a ratio η, identical to that of the outgoing and incoming currents . This ratio, called the "transformation ratio", is very often identified with a ratio of the number of turns, and is real and independent of frequency. The direction...