Top Banner
Constructing Prototype Lock-in Amplifier with LabVIEW & DAQ Xiaoyu Wu 08300290011 Dept. of Physics, Fudan University
9

Constructing Prototype Lock-in Amplifier with LabVIEW & DAQ

Jan 06, 2016

Download

Documents

kevork

Constructing Prototype Lock-in Amplifier with LabVIEW & DAQ. Xiaoyu Wu 08300290011 Dept. of Physics, Fudan University. What is Lock-in Amplifier(LIA)?. Detect & Measure Signals Even with overwhelming noise Typical S/N ratio -60dB. Signal + Noise. Amplitude + Phase as DC. - PowerPoint PPT Presentation
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Page 1: Constructing Prototype Lock-in Amplifier with  LabVIEW & DAQ

Constructing Prototype Lock-in Amplifier with LabVIEW & DAQ

Xiaoyu Wu08300290011

Dept. of Physics, Fudan University

Page 2: Constructing Prototype Lock-in Amplifier with  LabVIEW & DAQ

What is Lock-in Amplifier(LIA)?

• Detect & Measure Signals• Even with overwhelming noise• Typical S/N ratio -60dB

Signal + Noise

Amplitude + Phase as DC

Page 3: Constructing Prototype Lock-in Amplifier with  LabVIEW & DAQ

Typical Application: Scanning Tunneling Spectroscopy

Page 4: Constructing Prototype Lock-in Amplifier with  LabVIEW & DAQ

Principle of LIA

• Phase Sensitive Detection• Orthogonality of Sinusoidal Functions

LOW-PASS FILTER

Page 5: Constructing Prototype Lock-in Amplifier with  LabVIEW & DAQ

LabVIEW & DAQ

Page 6: Constructing Prototype Lock-in Amplifier with  LabVIEW & DAQ

Realizing the Algorithm

Page 7: Constructing Prototype Lock-in Amplifier with  LabVIEW & DAQ

Demonstration

Page 8: Constructing Prototype Lock-in Amplifier with  LabVIEW & DAQ

Features

• Signal Frequency: ~Hz to ~kHz• Signal Amplitude: 0.005V tested• Sampling Rate: maximum 50kHz, 40kHz tested

Page 9: Constructing Prototype Lock-in Amplifier with  LabVIEW & DAQ

Drawbacks

• S/N Ratio• Function Generator