Research On Weak Signal Detection Technology Based On USB3.0

Weak signal detection is a research hotspot in the field of measurement technology.It is a technical subject that uses electronics and signal processing technology to separate useful signals from complex noise backgrounds.It has been widely used in aerospace,remote sensing,medical and other fields.In this paper,a weak signal detection system based on USB3.0,which includes an analog lock-in amplifier module and a high-speed data acquisition module,is designed for the evaluation of superconducting materials at extremely low temperatures.And it can realize the weak signal detection and acquisition.The analog lock-in amplifier adopts low-noise amplification technology,filtering technology,phase-shifting technology and phase-sensitive detection technology to design signal channels,reference channel and correlators.The high-speed data acquisition module is designed with USB3.0 interface technology and FPGA.Data acquisition and transmission adopts a full hardware operation mode,which has the advantages of high-speed and stable transmission and real-time monitoring.The lock-in amplifier hardware circuit mainly includes pre-amplifier,band-pass filter,phase shifter,phase sensitive detection(PSD)and low-pass filter.The data acquisition module mainly includes signal preprocessing(signal conditioning,sampling),FPGA configuration(clock,buffer,etc.)and USB3.0 interface configuration.The analog circuit and digital circuit of acquisition module is supplied power separately.The system architecture is summarized in FPGA logic design,introduces the design of CYUSB3014 firmware,driver and interface design of upper computer.The software and hardware co-debug,and the experimental results show that the lock-in amplifier can detect n A at 1k Hz.The data acquisition system can realize data transmission accurately and stably.