원문정보
초록
영어
The phase-locked amplifier with output stability can filter out the noise effectively and the weak signal will be extracted from the noise and be amplified. The signal processing is relatively simple, so it is an effective way to detect the weak signal. It uses the phase sensitive detector (Phase Sensitive Detection, PSD) technique to identify the test signal, which has same frequency with the reference signal, and eliminate the interference noise signal of different frequency, so as to accurately measure the size of the measured signal. In this paper, switching correlator is taken as a core part of lock-in amplifier with large dynamic range, strong anti-overload and no non-linear problems. Moreover, lock-in amplifier output signal amplitude has no impact from the amplitude of the reference .
목차
1. Introduction
2. Principles of Week Signal Detection
3. The Overall Design of Phase-locked Amplifier
4. Unit Circuit Design
4.1 Low-noise Pre-amplifier
4.2 Tracking Band-pass Filter
4.3 Reference Channel Amplifier Design
4.4 PLL Design
4.5 The Correlator Circuit Design
4.6 Voltage Detection and Display
5. Circuit debugging and Results
6. Conclusion
References