Context
Contactless Induction Energy Transfer Systems for Medium Power Applications

Remote energy transfer techniques can be classified into different categories, depending on the distance from the source, relative to the wavelength λ. A distinction is made between near-field and far-field techniques. When the distances to be covered are small compared with λ, energy transfer takes place under near-field conditions. Conversely, when the distances to be covered are very large compared with λ, energy transfer takes place under far-field conditions. There is also an intermediate zone, called the transition zone, in which the electromagnetic (EM) field exhibits both near-field and far-field characteristics.

A distinction is made between three non-contact energy transfer techniques, within which one or more technologies may exist: