CAJ | 학술논문

介绍了一种微弱信号的检测与锁定放大方法。通过模拟锁相环工作锁定待检微弱信号的频率，利用控制器测量该锁相环的输出频率，并根据该频率值控制直接数字合成电路产生同频信号，该信号作为相关检测所需的参考信号。系统采用乘法器和积分电路实现相关检测，通过步进调整参考信号的相位，使互相关值最大，获得与被测信号同频同相的再生信号，从而实现微弱信号的检测与放大。该方法能够实现频率检测及幅度检测等功能。经实验测试表明：在低信噪比条件下，该方法仍具有较好的线性测量特性和较高的准确度，可实现任意波形的微弱信号自动检测和再生放大。
개소료일충미약신호적검측여쇄정방대방법。통과모의쇄상배공작쇄정대검미약신호적빈솔，이용공제기측량해쇄상배적수출빈솔，병근거해빈솔치공제직접수자합성전로산생동빈신호，해신호작위상관검측소수적삼고신호。계통채용승법기화적분전로실현상관검측，통과보진조정삼고신호적상위，사호상관치최대，획득여피측신호동빈동상적재생신호，종이실현미약신호적검측여방대。해방법능구실현빈솔검측급폭도검측등공능。경실험측시표명：재저신조비조건하，해방법잉구유교호적선성측량특성화교고적준학도，가실현임의파형적미약신호자동검측화재생방대。
The method of detecting weak signal and designing lock-in amplifier circuit was proposed , in which , having weak signal frequency obtained through analog PLL technology and the controller employed to detect phase-locked loop ’ s output frequency so that a reference signal for relevant detection can be obtained according to the same frequency produced by the frequency value-based direct digital synthesis circuit .The system employs multiplier and integrator to accomplish the relevant detection , and through adjusting the refer-ence signal step by step , the cross-correlation value can be maximized and the regeneration signal same as the measured signal in both frequency and phase can be obtained to implement detection and amplification of the weak signal , including both frequency and amplitude detection of the weak signal .The experimental tests show that this method has a high linearity at low SNR conditions and can be applied to the auto-detection and regen-erative amplification of the arbitrary waveform ’ s weak signal .