DocumentCode :
1320931
Title :
Analytical Expressions for the Readback Signal of Timing-Based Servo Schemes
Author :
Furrer, Simeon ; Jubert, Pierre-Olivier ; Cherubini, Giovanni ; Cideciyan, Roy D. ; Lantz, Mark A.
Author_Institution :
IBM Res.-Zurich Res. Lab., Ruschlikon, Switzerland
Volume :
48
Issue :
11
fYear :
2012
Firstpage :
4578
Lastpage :
4581
Abstract :
Timing-based servo (TBS) is a powerful technology widely used in state-of-the-art tape systems for track following. To optimize TBS systems for future operating points with aggressive track-density scaling, an accurate model is needed to characterize how the servo read head geometry, servo format parameters, and magnetic media properties affect the readback signal. In this paper, we derive new analytical closed-form expressions for the readback signal of shielded magneto-resistive (MR) heads scanning over the magnetic transitions of TBS patterns. The expressions, derived via the reciprocity principle, are applicable to arctan-shaped transitions between arbitrarily magnetized areas of a thin-film magnetic medium and are given in the displacement and wavevector domain. We apply these new expressions to analyze isolated transitions as well as multi-transition TBS patterns on longitudinal, non-oriented or perpendicular media. Comparison between experimentally captured servo readback signals and the analytical expressions show an excellent match. By adding electronics and transition jitter noise, the readback signal expressions can be extended to a servo channel model suitable for TBS performance prediction by means of Monte Carlo simulations and/or bounds on the variance of the position-error signal.
Keywords :
magnetic tape storage; magnetoresistive devices; servomechanisms; tape recorders; aggressive track-density scaling; analytical expressions; arctan-shaped transitions; closed-form expressions; magnetic media properties; magnetic transitions; multitransition TBS patterns; position error signal; readback signal expressions; reciprocity principle; servo channel model; servo format parameters; servo read head geometry; shielded magneto-resistive heads scanning; tape systems; thin-film magnetic medium; timing-based servo schemes; track following; transition jitter noise; wavevector domain; Magnetic domains; Magnetic heads; Magnetic noise; Media; Perpendicular magnetic recording; Servomotors; Magnetic recording; magnetic tape recording; modeling; servo;
fLanguage :
English
Journal_Title :
Magnetics, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9464
Type :
jour
DOI :
10.1109/TMAG.2012.2195647
Filename :
6332712
Link To Document :
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