Effects of thickness on properties of high frequency piezoelectric ultrasonic transducers
Piezoelectric ultrasonic transducer is a device to realize the conversion between electric energy and mechanical energy. The core element of the transducer is piezoelectric material, which directly affects the performance of transducer. High frequency ultrasonic transducers have higher resolution, and can recognize smaller size targets. The performances of the transducer are dependent on the frequency characteristics. The results show that the relative permittivity, piezoelectric strain constant, piezoelectric voltage constant and mechanical quality factor of the piezoelectric transducer increase with increasing thickness of piezoelectric material, and the thickness electromechanical coupling properties and resonant frequency decrease with increasing thickness. In the pulse response test of the transducers, with increasing thickness of the piezoelectric material, the transmitted time and peak-peak value of the ultrasonic wave received by the transducer increase, and the dominant frequency shows the decreasing trend.