Implementing spin-torque oscillator sensing with enhanced integrated demodulator for hard disk drives
US8570677B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 9, 2011 |
| Grant date | Oct 29, 2013 |
| Priority date | — |
| Expiry date | May 1, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/2516
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method, apparatus, and system are provided for implementing spin-torque oscillator sensing with an enhanced integrated demodulator for hard disk drives. The demodulator receives an input signal from a STO read sensor having an oscillation frequency ω related to the strength of the detected magnetic signal field. The demodulator includes a pair of mixers coupled to a quadrature reference oscillator with respective quadrature components cos(ω0t), and sin(ω0t) of the quadrature reference oscillator being mixed with a received input signal to form signals at the sum and difference frequencies, ω±ω0. Each of these mixer products is lowpass filtered by a respective a lowpass filter to remove the sum frequency components for providing a demodulator output signal that is directly proportional the STO oscillation frequency ω. The demodulator output signal is used for processing by data detection electronics.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.