文件名称：Lock-in Amplifier.pdf
文件大小：378KB
文件格式：PDF
更新时间：2022-12-27 05:45:22
lock in amplifie 锁相放大器
There are a number of ways of visualising the operation and significance of a lock-in amplifier. As an introduction to the subject there follows a simple intuitive account biased towards light measurement applications. All lock-in amplifiers, whether analogue or digital, rely on the concept of phase sensitive detection for their operation. Stated simply, phase sensitive detection refers to the demodulation or rectification of an ac signal by a circuit which is controlled by a reference waveform derived from the device which caused the signal to be modulated. The phase sensitive detector effectively responds to signals which are coherent (same frequency and phase) with the reference waveform and rejects all others.