Weak magnetic field measurement device and method based on modal localization effect

Abstract

The invention discloses a high-sensitivity magnetic field measurement method and device and belongs to the field of an electronic measurement instrument. The device comprises a magnetic field measurement chip and a test signal processing method. The chip comprises at least two weakly coupled resonators, a driving electrode, a detection electrode and an outer gate-type structure. The AC current isapplied to the weakly coupled resonators through a driving electrode, and when the chip is placed in a vertical magnetic field, the resonators are subjected to changed Lorentz force to generate simpleharmonic vibration; when the external magnetic field changes, a vibration state of the resonators changes accordingly, moreover, the DC current is applied to the gate-type structure, the gate-type structure is subjected to Lorentz force in the horizontal direction, and the electrostatic negative stiffness between the gate-type structure and the weakly coupled resonators is changed, so energy distribution of a weakly coupled resonator system is severely unbalanced. Two sets of detection electrodes are designed on two sides of an output resonator, single-resonator amplitude difference detectionis achieved, feed-through capacitance interference is eliminated, and high-sensitivity measurement of the weak magnetic field intensity can be achieved by measuring resonator amplitude difference. The device is advantaged in that real-time measurement of the weak magnetic field can be realized, the anti-interference capability is high, and use significance is high.

Description

[0001] Field: [0002] The invention relates to a high-precision weak magnetic field measuring device under a new theory and a corresponding testing method, belonging to the field of electronic measuring instruments. Background technique [0003] Beginning with Sinan in ancient times, humans have been detecting and applying magnetic field strength for thousands of years. Since modern times, magnetic field strength detection has important application requirements in many fields of scientific research and engineering technology, especially in the field of aerospace navigation systems. A magnetometer is an electronic instrument that can measure the strength and direction of the surrounding magnetic field at the same time, and the magnetometer under the micromechanical electronic process (MEMS) has become the current A hot spot in magnetometer research. [0004] In principle, some MEMS magnetometers use permanent magnets to measure magnetic field strength by combining electron t...

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Problems solved by technology

[0005] Among the MEMS magnetometers based on the Lorentz force, a class of magnetometers based on amplitude modulation has achieved an ultra-high sensitivity of 30nT / Hz and has a good quality factor, but the disadvantage is that its dynamic range is small. In practical applications, the measurement range is limited, so it is difficult to apply to various scenarios

Compared with the former, another type of magnetometer based on frequency modulation has a better dynamic range, but there is a frequency drift problem in the measurement process, which will greatly affect the sensitivity and resolution of this type of device, and it is difficult to achieve high precision

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