Patent ID: 7333290

Claim:
A magnetic disk having servo sectors for defining data tracks on the magnetic disk, each servo sector comprising: a preamble field for synchronizing a phase-locked oscillator during a servo sector read operation, wherein the preamble field defines a reference phase angle, and a null servo burst field comprising first and second servo bursts, wherein: the first and second servo bursts are radially adjacent and have opposed phase angles such that a read along a null path that is equally between the first and second servo bursts generates a read signal of substantially zero amplitude, and a read along a path that is offset from the null path generates a read signal having an amplitude indicating a distance between the offset path and the null path, and having a phase indicating an offset direction, the phase angle of the first servo burst is substantially different from the reference phase angle, and the phase angle of the second servo burst is substantially different from the reference phase angle.