The multimode coupled vibration transducer with the higher emission performances at resonant frequencies

The majority of existing piezoelectric transducers work at a single resonant frequency, and their applications in scenarios with multi-frequency or frequency variation are not fully considered. Moreover, emitting high-energy ultrasound at different frequencies is also crucial. Here, we propose the three-frequency coupled vibration piezoelectric transducer, which exhibits higher emission performances. The proposed transducer is comprised of two rectangular piezoelectric ceramics, which are cut from a piece of rectangular piezoelectric ceramic. We derive the three-dimensional coupled vibration electromechanical equivalent circuit of the proposed transducer. Then, the characteristics of the transducer are numerically simulated. And comparison experiments between the proposed transducer and a piece of rectangular piezoelectric ceramic transducer were done. An ultrasonic water tank measurement system was used to measure their sound field, axial sound pressure, and transmitting voltage response. Experiments are conducted to verify the electromechanical and sound field characteristics of transducers, which are in good agreement with the simulated results and theoretical predictions. The proposed transducer can generate stable and stronger energy ultrasonic waves at three resonant frequencies. And this study can provide the theoretical and experimental references for multi-frequency conversion and high-energy ultrasonic radiation of the transducer.