The test circuit construction and noise suppression for giant magneto-impedance sensor

Abstract-Based on the giant magneto-impedance (GMI) effect, we designed a magnetic sensor utilizing the field-annealed amorphous ribbon as the sensing element. This paper gives the comprehensive analysis of the GMI sensor´ s performance. A coil is applied to generate a bias magnetic field so that the sensor can detect both the positive and negative magnetic field. Another coil as the negative feedback coil is used to improve the linearity of the sensor output. The performances of the sensor were carefully studied with and without applying negative feedback. On applying the negative feedback the sensor shows excellent linearity and good stability. The full measurement range of the magnetic field detection is ±10e, and the sensitivity achieves 219mV/Oe, The relative linearity is about 10.8%.