1/f noise suppression of giant magnetoresistive sensors with vertical motion flux modulation

The 1/f resistance noise is one of the main noise sources of giant magnetoresistive sensors, which will cause intrinsic detection limit at low frequency. To suppress this noise, a vertical motion flux modulation (VMFM) scheme with high efficiency and simple structures is proposed. And the electrical coupling effect is investigated with an equivalent circuit model. We found that the electrical coupling disturbance can be suppressed by improving the symmetry of VMFM sensors. The modulation efficiency of VMFM sensors has reached 18.8%, which is higher than most prototype sensors with other flux modulation schemes.