Based On The Gmi Effect Of Weak Magnetic Sensor Research

Giant Magneto-Impedance (GMI) effect is a new phenomenon founded in the field of soft magnetic materials in the 1990s.The new type of magnetic sensor with high sensitivity, quick response and low power consumption, can be developed by GMI effect. Compared with the wide range of magnetic sensors, such as fluxgate sensors, Hall magnetic sensors, Giant Magneto-Resistive(GMR) sensors, Giant Magneto-Impedance has many obvious advantages. Due to the promising applications, the mechanism, the development of new materials and new technologies have attracted comparative research interest in the field of soft magnetic materials., GMI effect has even more enormous foreground of application.First this article aims to research fundamental theory of the GMI phenomena, the processing and characteristics of GMI materials, the factors that influenced on GMI effect. Then expatiates the sensor principle based on GMI. On the basis of GMI, the weak magnetic sensor is designed, which is composed of the excitation signal circuit, wave detection circuit, amplifier filter circuit, verified the circuit design, optimized the circuit parameters by circuit simulation software OrCAD/PSpice. The sensor circuit has been completed.Finally, a test has been completed on the characteristics of the magnetic sensor. The test turned out that the sensor has eminent properties such as excellent linearity and good repeatability, within a certain magnetic field. The sensor can be used in the weak magnetic measurement field including earth magnetic field and environmental magnetic field.