New Airborne Ultrasonic Transducer with High Output Sound Pressure Level

Abstract

To design a higher output ultrasonic sensor, reduction of stress in a piezoelectric element is required. For this purpose, a new transducer with vibrating parts for an ultrasonic sensor is proposed in this paper, in which we utilize an annular piezoelectric element bonded on three kinds of plates, stainless steel, titanium and aluminum, vibrating at its fundamental flexural mode. Our fabricated model gave a 10 to 20 dB higher output sound pressure level compared with a conventional enclosed-type ultrasonic transducer. From the results of our study, the output sound pressure level can be increased much more by selecting the material of the vibrating plate.