Origin of linear and nonlinear giant magnetoimpedance

It has gradually become clear that giant magnetoimpedance, which initially appeared very mysterious, can be explained classically, as arising from the dependence of skin depth upon the magnetic permeability. As the permeability may vary with dc field or with frequency, the impedance will vary as a function of these parameters. Thus, a variety of circumstances may give rise to GMI. A number of these circumstances are considered. The equivalence of GMI and ferromagnetic resonance calculations is discussed. On the basis of this equivalence, some effects are predicted.