Numerical analysis of ferrite recording heads with complex permeability

Numerical methods based on finite differences are applied to the analysis of ferrite recording heads in which the permeability is complex and flux leakage effects are significant. The methods described allow computation of head efficiency, inductance, loss angle, and phase shift. As a specific example, the analysis is performed for a reduced track width version of the Memorex 3650 head for a wide range of the real and imaginary parts of the permeability. Using published values for the frequency dependence of the complex permeability, the frequency dependence of the head performance is estimated. Some experimental data are presented and compared to the theoretical predictions.