Research on Nonlinear Equivalent Circuit of High Power Piezoelectric Transducer

According to the Mason's equivalent circuit of piezoelectric thickness-mode transducer, transmission line theory and high field dielectric behavior, a nonlinear PSPICE equivalent circuit model was proposed in this paper. This model can reflect the dielectric loss and simulate the nonlinearity of piezoelectric transducer under high electric field by building variable capacitor and resistor, whose values are affected by the level of the input exciting voltage. By establishing the nonlinear equivalent circuit model of high-power piezoelectric transducers in PSPICE tool, the nonlinear characteristic of the transducers under high voltage excitation were analyzed, and impedance matching was carried out, so as to improve the frequency response and bandwidth of the transducers in nonlinear conditions.