Modelling the asymmetry of the recorded transition zone in digitalmagnetic recording

A vector model of the recorded transition zone for digital magnetic recording is used to incorporate asymmetric transition profiles, non-constant recording contours and both longitudinal and perpendicular components of magnetization into a channel model. These factors all contribute to the asymmetry of the recording zone and hence the asymmetry of replay pulses and the associated nonlinear channel phase response. The use of the model for evaluation of channel spectra is examined. In particular it is found that good fits to experimental results for a typical recording channel are provided by a linear recording contour in conjunction with an arctangent transition profile. This model is useful for inclusion in a full digital magnetic recording system model since analytic expressions are available for both the replay pulse and its spectrum