Harmonic analysis of nonlinear MR head transfer characteristics

The voltage transfer characteristic of an MR magnetic recording read head is intrinsically nonlinear. This can compromise error-rate performance. The nonlinearity can be modeled by a linear, quadratic, and cubic term in sensitivity to field from the medium. This paper describes a theoretical and experimental quantification of the cubic nonlinearity associated with head saturation. The characterization can be carried out on any teststand. It employs a technique previously used to characterize high density nonlinear transition interactions (write nonlinearity), but in the present application characterizes low density nonlinearity associated with the read head