It is difficult to detect the signal of giant magneto-impedance (GMI) magnetic sensors with the signal-to-noise ratio (SNR) less than 0 dB by the conventional detection methods. In this paper, a novel detection circuit of a GMI sensor is presented, which directly samples the conditioned signals from the GMI sensor into a digital signal processing system and then a hybrid method combining wavelet transform with correlation analysis is proposed, which is proved effective for measuring the weak magnetic field even when the SNR of the GMI sensor signals is as weak as −15 dB.
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KuzminskiMNesterukKLachowiczHK (2008) Magnetic field meter based on giant magnetoimpedance effect. Sensors and Actuators A141: 68–75.
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MahdiAEPaninaLMappsD (2003) Some new horizons in magnetic sensing: high-Tc SQUIDs, GMR and GMI materials. Sensors and Actuators A105: 271–285.
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11.
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