Design and Fabrication of the High Directional Ultrasonic Ranging Sensor to Enhance the Spatial Resolution

A new ultrasonic ranging transducer with high directionality is developed to enhance the spatial resolution in the pulse-echo measurement in air. The concept of the parametric transmitting array is applied to the design. A high-performance piezoelectric micro-machined ultrasonic transducer (pMUT) array is designed and fabricated in this study. The indirectly generated pulse has a beam-width of around 5deg and a sound pressure level (SPL) of over 85 dB at the peak. For a practical application, the higher sound pressure level should be achieved.