title: Development of a low noise induction magnetic sensor using magnetic flux negative feedback in the time domain.
abstract: Time-domain electromagnetic system can implement great depth detection. As for the electromagnetic system, the receiver utilized an air coil sensor, and the matching mode of the sensor employed the resistance matching method. By using the resistance matching method, the vibration of the coil in the time domain can be effectively controlled. However, the noise of the sensor, especially the noise at the resonance frequency, will be increased as well. In this paper, a novel design of a low noise induction coil sensor is proposed, and the experimental data and noise characteristics are provided. The sensor is designed based on the principle that the amplified voltage will be converted to current under the influence of the feedback resistance of the coil. The feedback loop around the induction coil exerts a magnetic field and sends the negative feedback signal to the sensor. The paper analyses the influence of the closed magnetic feedback loop on both the bandwidth and the noise of the sensor. The signal-to-noise ratio is improved dramatically.
authors.affiliation: College of Instrumentation and Electrical Engineering, Jilin University, Changchun 130061, People's Republic of China.
authors.forename: X G
authors.initials: XG
authors.lastname: Wang
authors.affiliation: College of Instrumentation and Electrical Engineering, Jilin University, Changchun 130061, People's Republic of China.
authors.forename: X L
authors.initials: XL
authors.lastname: Shang
authors.affiliation: College of Instrumentation and Electrical Engineering, Jilin University, Changchun 130061, People's Republic of China.
authors.forename: J
authors.initials: J
authors.lastname: Lin