{"title":"低频感应磁力计的低噪声斩波放大器设计","authors":"Yao Tang, Zhenzhu Xi, Xingpeng Chen, Xia Long","doi":"10.1093/jge/gxad082","DOIUrl":null,"url":null,"abstract":"Abstract Induction Magnetometers (IM) are commonly used in Magnetotelluric Method for exploration. 1/f noise in the low frequency band of the preamplifier reduce the signal-to-noise ratio of IM, thus affecting the exploration results. We designed a low noise chopper amplifier with equivalent input voltage noise of 9.8 nV/√Hz at 1 mHz, 2.1 nV/√Hz at 0.01 Hz, 1.9 nV/√Hz at 0.1 Hz, 1/f noise corner frequency of 8 mHz, and equivalent input current noise of 200 fA/√Hz at 1 mHz, 100 fA/√Hz at 0.01 Hz, 60 fA/√Hz at 0.1 Hz. The IM using this chopper amplifier is 85.5 cm long, 6.0 cm in diameter and has a total weight of 4.8 kg. Its sensitivity is 300 mV/nT during 20 Hz and 1 kHz, with a theoretical equivalent input magnetic field noise of 0.3 pT/√Hz at 1 Hz and a measurement frequency range of 1 mHz to 1 kHz.","PeriodicalId":54820,"journal":{"name":"Journal of Geophysics and Engineering","volume":null,"pages":null},"PeriodicalIF":1.6000,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Low noise chopper amplifier design for low frequency Induction Magnetometers\",\"authors\":\"Yao Tang, Zhenzhu Xi, Xingpeng Chen, Xia Long\",\"doi\":\"10.1093/jge/gxad082\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Abstract Induction Magnetometers (IM) are commonly used in Magnetotelluric Method for exploration. 1/f noise in the low frequency band of the preamplifier reduce the signal-to-noise ratio of IM, thus affecting the exploration results. We designed a low noise chopper amplifier with equivalent input voltage noise of 9.8 nV/√Hz at 1 mHz, 2.1 nV/√Hz at 0.01 Hz, 1.9 nV/√Hz at 0.1 Hz, 1/f noise corner frequency of 8 mHz, and equivalent input current noise of 200 fA/√Hz at 1 mHz, 100 fA/√Hz at 0.01 Hz, 60 fA/√Hz at 0.1 Hz. The IM using this chopper amplifier is 85.5 cm long, 6.0 cm in diameter and has a total weight of 4.8 kg. Its sensitivity is 300 mV/nT during 20 Hz and 1 kHz, with a theoretical equivalent input magnetic field noise of 0.3 pT/√Hz at 1 Hz and a measurement frequency range of 1 mHz to 1 kHz.\",\"PeriodicalId\":54820,\"journal\":{\"name\":\"Journal of Geophysics and Engineering\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.6000,\"publicationDate\":\"2023-10-18\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Geophysics and Engineering\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1093/jge/gxad082\",\"RegionNum\":3,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"GEOCHEMISTRY & GEOPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Geophysics and Engineering","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1093/jge/gxad082","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
Low noise chopper amplifier design for low frequency Induction Magnetometers
Abstract Induction Magnetometers (IM) are commonly used in Magnetotelluric Method for exploration. 1/f noise in the low frequency band of the preamplifier reduce the signal-to-noise ratio of IM, thus affecting the exploration results. We designed a low noise chopper amplifier with equivalent input voltage noise of 9.8 nV/√Hz at 1 mHz, 2.1 nV/√Hz at 0.01 Hz, 1.9 nV/√Hz at 0.1 Hz, 1/f noise corner frequency of 8 mHz, and equivalent input current noise of 200 fA/√Hz at 1 mHz, 100 fA/√Hz at 0.01 Hz, 60 fA/√Hz at 0.1 Hz. The IM using this chopper amplifier is 85.5 cm long, 6.0 cm in diameter and has a total weight of 4.8 kg. Its sensitivity is 300 mV/nT during 20 Hz and 1 kHz, with a theoretical equivalent input magnetic field noise of 0.3 pT/√Hz at 1 Hz and a measurement frequency range of 1 mHz to 1 kHz.
期刊介绍:
Journal of Geophysics and Engineering aims to promote research and developments in geophysics and related areas of engineering. It has a predominantly applied science and engineering focus, but solicits and accepts high-quality contributions in all earth-physics disciplines, including geodynamics, natural and controlled-source seismology, oil, gas and mineral exploration, petrophysics and reservoir geophysics. The journal covers those aspects of engineering that are closely related to geophysics, or on the targets and problems that geophysics addresses. Typically, this is engineering focused on the subsurface, particularly petroleum engineering, rock mechanics, geophysical software engineering, drilling technology, remote sensing, instrumentation and sensor design.