A position encoding and decoding scheme for ultra high density magnetic recording

Abstract

Abslract-With the increasing demands in the storage capacity and access speed of hard disk drive (HDD), data is recorded in ever-narrow tracks that must be followed with extreme precision. This paper presents an encoding and decoding scheme for more eiticient and accurate position sensing. The multiple frequencies servo pattern encoding allows an overall reduction of servo overhead and together with the high flexibility and sensitivity of the digital position sensing technique; precise track following on very narrow track is possible. This paves the way for ultra high track density magnetic recording. Index Terms-hard disk drive, position error signal (PES), servo pattern, servo demodulation.