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

With the increasing demands on the storage capacity and access speed of hard disk drives (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 efficient and accurate position sensing. The multiple-frequency 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 tracks is possible. This paves the way for ultra high track density magnetic recording.