Customizable coherent servo demodulation for disk drives

This paper describes the customizable coherent demodulation algorithm, a servo demodulator which provides dramatically improved performance over the currently used servo demodulation methods for disk drives. The demodulation algorithm proposed makes better use of knowledge about the read-back signal coming from the disk to provide better noise immunity and more immunity to other nonideal components in the magnetic head response. The net result is a demodulated position error signal which has a much cleaner response.