Servo format trend and servo channel improvement for high areal density
Guoxiao Guo, Jie Yu · Asia-Pacific Magnetic Recording Conference · 2010
This paper reviews the hard disk drive servo format (wedge number, servo frequency, and efficiency) trends and some improvement approaches in the perpendicular magnetic recording system. We observe that due to decreasing system signal to noise ratio at high areal density, servo channel signal processing gain is needed to maintain and improve servo format efficiency. A gray code error correction scheme is presented.