High-precision time measurement electronics using the bandpass sampling method.

Area of Science:

• Electrical Engineering
• Signal Processing
• Instrumentation

Background:

• High-precision time measurements are crucial in various scientific and engineering fields.
• Traditional methods often require very high sampling rates (giga-samples per second), increasing hardware complexity and cost.
• There is a growing research interest in achieving high timing precision at lower sampling rates.

Purpose of the Study:

• To develop a time measurement system capable of high precision at a lower sampling rate (around 100 MSps).
• To investigate the application of bandpass sampling for enhanced timing accuracy.
• To design and implement a real-time time extraction algorithm suitable for low-sampling-rate systems.

Main Methods:

• An analog front-end circuit was designed for bandpass filtering and amplification of input pulse signals.
• A pipelined real-time time extraction algorithm was developed, incorporating interpolation and cross-correlation techniques.
• A 1024-point fast Fourier transform (FFT) was utilized for efficient cross-correlation computation.
• Four time measurement channels were implemented on a mid-range field-programmable gate array (FPGA).

Main Results:

• The system successfully achieved high-precision time measurements at a sampling rate of approximately 100 MSps.
• A measurement rate of 116 kHz was attained with the FPGA implementation.
• The typical Root Mean Square (RMS) precision of the timing system was demonstrated to be better than 0.4 picoseconds.

Conclusions:

• The bandpass sampling method is effective for achieving high-precision time measurements at reduced sampling rates.
• The developed real-time algorithm and FPGA implementation provide a practical solution for advanced timing applications.
• The achieved sub-picosecond precision opens possibilities for more cost-effective and accessible high-resolution timing systems.