A multi-phase time-zooming high-precision ultrasonic water flow meter

In this study, we have developed a high-precision ultrasonic water flow meter with a 0.18 µm standard CMOS technology. Three methods are proposed to improve the performance: implementation of an active bandpass filter, threshold voltage optimization, and integration of a multi-phase time-zooming technique. The active bandpass filter effectively reduces noise in the received signal, thereby contributing to the overall accuracy of propagation measurements. Based on a threshold voltage generator, our proposed system identifies the optimum threshold voltage, ensuring robust noise durability. Furthermore, we have extended the conventional time-zooming technique by incorporating multiple phases of internal clocks. This innovative multiphase time-zooming technique offers a theoretical improvement in time resolution. The results demonstrate a remarkable suppression of flow rate measurement variations, achieving an impressive reduction to 1/10th of the original values. This affirms the effectiveness of the developed ultrasonic water flow meter in ensuring precise and reliable flow rate measurements.