An embedded magnetic field sensing device utilizing giant magnetoimpedance (GMI) effect

This paper aims at developing an embedded giant magnetoimpedance (GMI) sensing device using balanced modulator/demodulator topologies. Its prototype compact model which is suitable for in-situ applications is fabricated by integrating the probe assembly and the processing circuits. The device measures the phase shift which in turn calibrates the magnitude of the magnetic field. Balanced modulator/demodulator topologies are incorporated for phase shift measurement which not only enhances the sensitivity of the sensing device due to the improvement of the signal to noise ratio but also improves the repeatability and reproducibility of the sensing device. The characterization results and the performance evaluations are included to demonstrate the improved performance of the sensing device.