Transition shape and nonlinear effects in digital magnetic recording on thin film media

Abstract

Nonlinearities in square wave recording on three rigid disks have been studied experimentally. Measurements of the roll-off curves and of the noise power spectra as functions of packing density both show that in square wave recording nonlinearities arise from transition width broadening at high densities. Transition width parameters measured by the two methods show excellent agreement over the whole range of packing densities studied.

Recorded magnetization distributions in thin film disk media

“…However, the successful theories of noise are still based on the assumptions of arctangent transitions [12]- [14], and these have been shown to have good agreement with experimental observations of both noise spectra and total noise powers, at least until the onset of supra-linear noise at high densities. Therefore, it seems, overall, that while the sawtooth nature of transitions is very evident, the use of arctangent theory has persisted and that even in circumstances where the transitions do not at least superficially appear to be of arctangent nature, the arctangent theory still enjoys some success.…”