A theoretical study of the signal response of a shielded MR sensor [magnetic heads]

A general analysis of the behavior of a shielded magnetic-field biased magnetoresistive sensor is presented. Using a transmission-line model and assuming linear magnetic behavior for the MR sensor material, the nature of the MR transfer curve and the dependence of output amplitude and asymmetry on bias levels and signal strengths is studied. Results show that, in general, there is no single optimum bias level that simultaneously maximizes the small-signal response amplitude and minimizes the positive-negative output asymmetry. As a result, in MR head designs, compromise must be made according to the relative importance of these two objectives