Frequency characteristics of a regulatable piezoelectric transducer with external LC circuit

Piezoelectric transducers are often affected by temperature and load,resulting in changes in their characteristic parameters such as resonance frequency,anti-resonance frequency and mechanical quality factor.By designing the piezoelectric ceramics for regulation in the piezoelectric transducer,and connecting the electrical load at both ends of the regulating piezoelectric ceramics,the frequency regulation of the piezoelectric transducer can be realized,and the frequency drift caused by temperature and load can be corrected.Based on the Mason equivalent circuit of piezoelectric transducer,the resonant frequency and anti-resonant frequency models of piezoelectric transducer with external LC regulating circuit are established,and the influence of regulating inductance in LC regulating circuit on frequency regulation characteristics is analyzed.The influence of external LC regulating circuit on the mechanical quality factor of regulatable piezoelectric transducer is studied by experiments,and the influence of regulating inductance on frequency regulation characteristics is verified.The results of theoretical analysis and experimental studies show that as the regulating inductance increases,the regulating sensitivity of capacitance on frequency increases and the frequency regulation width of the regulatable piezoelectric transducer widens,but it also reduces the mechanical quality factor of the piezoelectric transducer.The reasonable selection of the regulating inductor and the regulating capacitor can balance the requirements of frequency regulation width and mechanical quality factor.This study can provide guidance for the design of subsequent frequency regulation systems for adaptive piezoelectric transducers.