FPGA-Based Digital Lock-in Amplifier With High-Precision Automatic Frequency Tracking
| Autor: | Huan Liu, Cheng Zhang, Haobin Dong, Jian Ge |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
weak signal detection
Signal generator DSP builder General Computer Science Noise (signal processing) Computer science business.industry Amplifier Lock-in amplifier General Engineering Signal digital lock-in amplifier Sine wave Electronic engineering General Materials Science lcsh:Electrical engineering. Electronics. Nuclear engineering business Digital filter Automatic frequency tracking lcsh:TK1-9971 Digital signal processing |
| Zdroj: | IEEE Access, Vol 8, Pp 123114-123122 (2020) |
| ISSN: | 2169-3536 |
| Popis: | Aiming to overcome the problem of the frequency error between the reference signal and the measured signal in an analog lock-in amplifier, this paper presented a digital lock-in amplifier (DLIA) with accurate frequency automatic tracking to improve its performance. In this paper, a modular design approach based on DSP Builder was employed to develop a quadrature vector type lock-in amplifier with automatic frequency tracking. A reference signal generator with high-frequency resolution and a digital filter with good performance were implemented. The performance of the design was tested by determining the linearity, the Q value, and the noise immunity of the DLIA. The experimental results showed that the proposed DLIA has good linearity and the Q value can reach up to 82. The relative errors of the signals with amplitudes greater than 10 mV were less than 1% when the equivalent input was a sine wave signal with a frequency of 1 kHz and an amplitude of 500 mV. When the superimposed noise was less than or equal to 400 mV, the relative error was less than 2% in the same condition. The proposed DLIA has higher precision and efficient noise immunity. |
| Databáze: | OpenAIRE |
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