Generalized gyrotropic media are characterized by four axes, three being the principal axes of the anisotropic media before application of the steady magnetic field

, and the fourth being the direction of

. They can be synthetically fabricated from an appropriately stratified pile of ferrite rods. Although much more complicated than for ordinary gyrotropic media (which are characterized by a single axis of

) the basic modes of radio propagation in such generalized media turn out to have some surprisingly simple properties. For example

, and the three principal directions of propagation of characteristically elliptically polarized planewaves, lie in a common plane. Formulas for these characteristic polarizations in terms of the tensor permeability are also very simple.