Low-noise MEMS pre-amplification device utilizing high-resolution magnetic field detection

Abstract

The invention discloses a low-noise MEMS pre-amplification device utilizing high-resolution magnetic field detection, which comprises an insulation substrate and a magnetic line of force collector, and is characterized in that the bottom surface of the magnetic line of force collector is wound with a bottom coil, the top surface of the magnetic line of force collector is wound with a top coil, the bottom coil and the top coil form a current coil which is wound on the magnetic line of force collector together, the magnetic line of force collector is of a concentric double square structure and formed by arranging two high-permeability components in an axial symmetry manner, the two high-permeability components are formed on the insulation substrate and grown by adopting a high-permeability material, a gap is reserved between the two high-permeability components, the insulation substrate is provided with a magnetic field sensitive element in the gap, and the insulation substrate is provided with a micro-voltage bridge modulation assembly located above the magnetic field sensitive element. The low-noise MEMS pre-amplification device can realize nV-level low noise amplification, and has the advantages of good magnetic field collecting and amplifying effect, good external magnetic field interference resistant performance, small size and high electric-magnetic signal conversion efficiency.

Description

technical field [0001] The invention relates to the technical field of weak signal detection, in particular to a low-noise MEMS preamplifier device using high-resolution magnetic field detection, which is used for preamplifying extremely low-frequency and low-noise weak electrical signals. Background technique [0002] The low-noise preamplifier is usually used as the first-stage amplifier circuit, and it has been widely used in various radio receivers and high-sensitivity electronic detection equipment. noise-related performance. Traditional low-noise amplifiers generally have obvious 1 / f noise characteristics due to the limitation of the inherent physical mechanism of silicon-based semiconductors. The lower the frequency, the greater the noise, resulting in the noise of low-noise amplifiers used for extremely low-frequency (<1Hz) signals. The level is difficult to reach the sub-nV level. In many cases where very low frequency weak signals need to be detected, it is di...

AI Technical Summary

Problems solved by technology

In order to achieve low-frequency and low-noise amplification, domestic and foreign patents are mainly realized through chopping modulation, and there is no research on other extremely low-frequency low-noise amplifiers based on new principles.

However, due to irrational characteristics such as clock collapse and charge injection, the output of the chopper amplifier will have a certain residual offset, which affects its performance.

It can be seen that the noise of the traditional low-noise amplifier reaches about 1nV / √Hz and it is difficult to continue to reduce, and the noise at extremely low frequencies may be even greater, which is difficult to meet the needs of some extremely low-frequency weak signal measurements

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