Nonlinear equivalent circuit of high-power sandwich piezoelectric ultrasonic transducer

• Published in: IEEE transactions on ultrasonics, ferroelectrics, and frequency control ferroelectrics, and frequency control, 2022-11, Vol.69 (11), p.1-1
• Main Authors: Yu, Jiawei, Xu, Long
• Format: Article
• Language: English
• Subjects: Acoustic velocity; Acoustics; Ceramics; Circuit design; Complex constants; Dielectrics; Equivalent circuits; FE simulation; Finite element method; Longitudinal waves; Mathematical models; nonlinear equivalent circuit; nonlinear resonance frequency equation; Parameters; Piezoelectric ceramics; Resonant frequency; sandwich piezoelectric ultrasonic transducer; Transducers; Ultrasonic transducers; Wavelengths
• ISSN: 0885-3010; 1525-8955
• DOI: 10.1109/TUFFC.2022.3208619

In the theoretical design and analysis of the sandwich piezoelectric ultrasonic transducer, the transducer is considered to be an ideal linear system, where the dielectric, piezoelectric and mechanical losses are neglected. However, when the transducer is driven at high power, the losses are becoming several times higher comparing them to low signal measurements, and the transducer works in a nonlinear state. In order to predict the performance of the transducer at high power, the nonlinear parameters (complex constants) of the piezoelectric materials are introduced. The corresponding nonlinear equivalent longitudinal wave sound velocity, the nonlinear equivalent longitudinal wave number of the piezoelectric ceramics are derived. Then the nonlinear equivalent circuit (NEC) and the nonlinear resonance frequency equation of the high-power sandwich piezoelectric ultrasonic transducer that related with the losses are deduced. Then, the nonlinear finite element model (NFEM) of the transducer is constructed. The performance parameters of the transducer obtained by the NEC method and the FE method are compared with each other, and consistent results have been achieved by two methods. Finally, the contribution of various losses is obtained through theoretical calculation, simulation and experimental measurement, and the correctness of the theoretical model in this paper is verified.