An open-source high-frequency lock-in amplifier

Area of Science:

• Electronics
• Instrumentation
• Signal Processing

Background:

• Lock-in amplifiers are crucial for extracting weak signals from noisy environments.
• Traditional lock-in amplifiers have limitations in frequency range and noise performance.

Purpose of the Study:

• To characterize a novel field-programmable gate array (FPGA) based lock-in amplifier.
• To evaluate its performance for high-frequency signal demodulation.

Main Methods:

• Characterization of a custom-built lock-in amplifier.
• Utilizing a field-programmable gate array (FPGA) for digital signal processing.
• Measurement of input noise and passband characteristics.

Main Results:

• The FPGA lock-in amplifier demonstrates effective demodulation up to 50 MHz.
• Achieved an input noise level of 90 nV/√Hz at an optimal frequency of 500 kHz.
• The system exhibits a 2.6 kHz passband width for modulation frequencies above 100 kHz.

Conclusions:

• The developed FPGA lock-in amplifier offers competitive performance for high-frequency measurements.
• The open-source nature and commercial platform compatibility enhance its accessibility and usability.
• This technology advances portable and high-performance signal detection.