an association of jitter noise spectra with reproduced waveform in perpendicular recording

摘要

Double-layered perpendicular recording media had two dominant medium noises, a transition jitter noise and a reversed domain noise. The transition jitter noise spectrum was delivered from the derivative of the transition shape, while the reversed domain noise spectrum was derived from the impulsive reversed domain. The noise enhancement in a low frequency region with increasing the recording density was caused by the jitter noise. The noise spectra from both origins should be whitened when the transition width and the reversed domain size became small. In the case, the noise spectrum was controlled by the channel characteristic including the head response, and the noise enhancement in a low frequency region by the jitter disappeared.