Nondispersive magnetostatic forward volume waves under field gradient control

The magnetostatic dispersion relation for a single ferrite strip of width W and thickness d, placed between arbitrarily spaced parallel ground planes, is derived under the assumption that the dc magnetic bias is normal to the plane of the strip but a general polynomial function of the transverse coordinate. Edge wave and volume wave modes are considered separately and both types are found to be susceptible to field gradient control. Assuming N-field gradient coefficients are available for dispersion control, a least-squares procedure can be employed to find that set which best approximates nondispersive (or other desired) propagation over a prescribed bandwidth. As expected, control is best achieved with moderately long magnetostatic wavelengths.