RECIPROCITY PRINCIPLES FOR MAGNETORESISTIVE HEADS

A generalized reciprocity principle for magnetoresistive (MR) heads is derived. The results apply primarily to the linear (small signal) reproduce performance of any MR head type (shielded or unshielded, single or multiple active MR elements) of arbitrary three-dimensional geometry. Reciprocity principles provide a powerful technique for calculating the intrinsic ''sensitivity function'' that is characteristic of a given MR reproduce head, and which in principle contains all information regarding the linearized reproduce response of the MR head with respect to any record medium of arbitrary recorded magnetization. The computational work required to evaluate the sensitivity function via reciprocity is a small fraction of that which would be required by direct means.