Broadband and low-noise differential amplification circuit for weak signal measurement

Abstract

The invention relates to a weak signal detection technology, aims to overcome the defects of narrow frequency band and high noise of a detection circuit for outputting weak signals by a marine sensor,and aims to provide a broadband and low-noise amplification circuit whichCan effectively amplify Nanoscale (nV) weak signals in a 0.1Hz-10MHz broadband range, and is low in the self noise level. Therefore, the technical scheme adopted by the invention is as follows: the broadband and low-noise differential amplification circuit for weak signal measurement comprises three stages of amplification circuits, the first stage amplification circuit adopts a proportional differential amplification circuit, the second stage amplification circuit adopts a high-pass filtering amplification circuit, andthe third stage amplification circuit adopts a proportional amplification circuit; And two paths of differential output of the first-stage amplifier respectively enter the in-phase input end and the inverted input end of the second-stage amplifier. The method is mainly applied to weak signal detection occasions.

Description

technical field [0001] The invention relates to a weak signal detection technology, in particular to a wide-band, low-noise differential amplifier circuit for weak signal measurement, which can effectively amplify the weak signal output by the front sensor of the electromagnetic current meter, and can also measure Noise floor levels in the frequency domain for various sensor materials. Background technique [0002] At present, in the research and development of current measuring instruments, the electromagnetic current meter uses the geomagnetic field as the excitation field source, and the self-equipment does not need to design the emission source, which makes the front-end probe lighter. Compared with other current measurement equipment, it is faster and more convenient, and is suitable for parameter measurement in various marine environments. For example, in the article "Development of Abandoned Ocean Current Electric Field Profiler" published by Zhang Qisheng et al. on ...

AI Technical Summary

Problems solved by technology

[0003] In order to overcome the deficiencies of the prior art, the detection circuit for the weak signal output by the marine sensor has the shortcomings of narrow frequency band and high noise. The present invention aims to propose a wide-band, low-noise amplifier circuit. It can effectively amplify nanoscale (nV) weak signals in a wide frequency range, and its own noise level is low

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