A magnetic-field sensor that provides an output signal in response to an external magnetic field is described. This magnetic-field sensor includes a pair of cantilevers separated by a horizontal gap, which is displaced vertically over an open cavity by applying a time-varying voltage having a fundamental frequency across piezoelectric layers in the pair of cantilevers. The pair of cantilevers also includes magnetic-flux concentrators that convey the external magnetic field to the horizontal gap between the pair of cantilevers. A stationary magnetoresistive sensor in the horizontal gap transforms the external magnetic field into an output signal. Because the pair of cantilevers is displaced vertically at the fundamental frequency, the output signal includes a modulation signal corresponding to the external magnetic field centered around twice the fundamental frequency. This modulation of the external magnetic field allows 1/f noise to be suppressed, thereby improving the sensitivity of the magnetic-field sensor.
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