夹心式压电超声复频换能器的研究

对具有多个共振频率的纵向振动夹心式压电超声换能器进行了研究，该换能器由多组压电陶瓷片及金属棒组成。在一维纵向振动理论及等效电路的基础上，推出了夹心复频超声换能器的共振频率方程，设计并制作了一些复频换能器，并对换能器的共振频率、有效机耦系数和等效电阻抗等参数进行了测试。

Study on the Multifrequency Sandwiched Piezoelectric Ultrasonic Transducer

Multifrequency sandwiched piezoelectric transducer consists of metal cylinder and piezoelectric ceramic pile. Based on the one dimension longitudinal vibration theory,the resonance frequency equation of the multifrequency transducer is derived out.Some transducers of this kind are designed and made,and the resonance frequencies,the equivalent electric impedance and the ef-fective electromechanical coupling coefficient are measured.Experiments show that the measured resonance frequencies of the transducers are in good agreement with calculated values. The trans-ducers can resonate at different frequencies with half wave and full wave vibrational modes.