Patent ID: 8570677

Claim:
A method for implementing data detection with spin-torque oscillator (STO) sensing with a demodulator for hard disk drives comprising: receiving an input signal from a STO read sensor having an oscillation frequency ω(t) related to magnetic field varying in time in response to a varying applied magnetic field; mixing a received input signal from said STO read sensor with respective quadrature signal components cos(ω 0 t), and sin(ω 0 t) to form signals at the sum and difference frequencies, ω±ω 0 ; lowpass filtering said signals at the sum and difference frequencies, ω±ω 0 by a respective lowpass filter for providing a demodulator output signal proportional to the STO oscillation frequency ω(t); said demodulator output signal used for processing by data detection electronics; providing a respective differentiation circuit receiving a resulting modulated signal from said respective lowpass filters and providing resulting differentiated signals.