Design of signal processing circuit of giant magneto-impedance sensor in target detection

In order to adapt to the high measurement precision and wide range in the field of target detecting in military, an improved signal processing circuit is proposed. To keep the secondary information of GMI (giant magneto-impedance) sensor's output signals, a two-order frequency mixing circuit is introduced, so except fundamental frequency features, the secondary frequency features and the wavelet coefficient features can also be detected, which is good to improve GMI sensor's measurement precision. Finally, the designed circuit is simulated to verify its rationality. Results show that when the target moves along a straight line, the prediction precision can be kept within ±3.67 %.