Research and validation of design principles for PVDF wideband ultrasonic transducers based on an equivalent circuit model

Abstract

With the increasing use of ultrasonic measurement technology in many fields, the demand for the wideband ultrasonic transducers is also growing. In order to design a wideband piezoelectric ultrasonic transducer, the design principles of wideband PVDF piezoelectric ultrasonic transducers are studied in this paper. A new equivalent circuit model of piezoelectric ultrasonic transducer is used here to simulate the piezoelectric ultrasonic transducer, which combines with the controlled source model and the lossy transmission line model. Based on this model, the relationships between physical structures and properties of PVDF transducers are studied both in simulation and experiment. It shows that the center frequency and many other property parameters of PVDF ultrasonic transducers are strongly related to the physical structures of it. Finally, a wideband PVDF piezoelectric ultrasonic transducer is produced with the center frequency of about 5.3 MHz ± 0.1 MHz and the bandwidth of more than 90%.