Ferrite resonance cones

Resonance cones, a phenomenon which has been observed in electrostatic plasma waves, should also exist in magnetostatic waves propagating in ferrites. Resonance cones, the spatial characteristics of the hyperbolic partial differential describing both plasma and ferrite waves, are aligned along the group velocity trajectory and are equivalent to the superposition of an infinity of normal modes. The existence of resonance cones has been overlooked in standard normal mode analyses of ferrite waves, where typically, only one mode is assumed to exist at a time.