Reducing hysteresis in magnetostrictive-piezoelectric magnetic sensors

In this paper, we present a method to avoid hysteresis in magnetostrictive-piezoelectric sensors. It is based on the application of an alternating magnetic field of a frequency different than the piezoelectric exciting frequency that supplies enough energy to overcome any domain wall pinning. The signal is filtered with a notch filter synchronized to the magnetic field frequency and thus it does not contribute to the useful response of the sensor. The results show an appreciable decrease in the magnetic hysteresis and also a small decrease in the sensitivity of the sensor