Ultra-low noise signal amplification circuit for capacitive ocean inert material electrode

Abstract

The invention provides an ultra-low noise signal amplification circuit for a capacitive ocean inert material electrode. The ultra-low noise signal amplification circuit comprises a chopping modulation circuit which is used for modulating an ultra-low frequency broadband weak signal into a high-frequency signal to avoid flicker noise of a subsequent signal processing circuit; a potential impedance matching circuit which is used for providing reference potential of a chopping modulation control signal and matching impedance of an electrode; a high input impedance differential alternating current amplification circuit which is used for performing low-noise differential amplification processing on a signal and converting a differential signal into a single-ended signal; a chopping demodulation circuit which is used for demodulating the high-frequency signal into a low-frequency signal and recovering an amplified low-frequency broadband signal; a low-pass filter circuit which is used for filtering high-frequency noise generated by modulation and demodulation; and a high input impedance direct current amplification circuit which is used for impedance matching of circuit output. The signal amplification circuit provided by the invention is an ultra-low noise signal amplification circuit for impedance matching of a capacitive electrode, and is suitable for signal detection of an easily polarized capacitive ocean inert material electrode.

Description

technical field [0001] The invention relates to the technical field of signal processing, in particular to an ultra-low noise signal amplifying circuit for capacitive marine inert material electrodes. Background technique [0002] As an effective supplement to marine seismic exploration, marine electromagnetic method is a research hotspot in the field of offshore oil and gas resource exploration, especially in the field of deep sea oil and gas resource exploration, which can effectively reduce the dry well rate of offshore oil and gas drilling. Marine electromagnetic signals include natural source electromagnetic signals and artificial source electromagnetic signals. Natural source marine electromagnetic signals are mainly generated by lightning, geomagnetic pulsations, submagnetic storms and magnetic storms. The frequency range of marine electromagnetic signals is about 0.001Hz-100Hz. Conductivity, the marine electromagnetic signal is severely attenuated, and the induced el...

AI Technical Summary

Problems solved by technology

Therefore, the current commonly used low-noise signal acquisition circuit connected to non-polarized Ag / AgCl electrodes cannot be directly applied to easily polarized carbon fiber electrodes.

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