Howtosignalprocessing
- What is the purpose of lock-in amplifier?
- What does a low pass filter do on an amplifier?
- How does a lock-in detector work?
- What is the purpose for dual phase lock-in amplifier?
What is the purpose of lock-in amplifier?
Lock-in amplifiers are used to detect and measure very small AC signalsall the way down to a few nanovolts. Accurate measurements may be made even when the small signal is obscured by noise sources many thousands of times larger.
What does a low pass filter do on an amplifier?
A low-pass filter (LPF) attenuates content above a cutoff frequency, allowing lower frequencies to pass through the filter. The slope of filter attenuation is usually quantified in decibels per octave.
How does a lock-in detector work?
They employ a homodyne detection scheme and low-pass filtering to measure a signal's amplitude and phase relative to a periodic reference. A lock-in measurement extracts signals in a defined frequency band around the reference frequency, efficiently rejecting all other frequency components.
What is the purpose for dual phase lock-in amplifier?
A complete digital dual-phase lock-in amplifier system based on DSP and LabVIEW was designed. It can extract the weak sinusoidal signals submerged by noise. This design has the advantages of high accuracy, low cost and portability, and its update and transplantation are easy.
