【摘要】 本文利用拉普拉斯变换、牛顿方程和压电方程,求出了厚度方式的压电换能器在用作接收和发射超声时的瞬态响应。计算了一个δ函数激励的例子,在忽略机电耦合系数k_t时它的瞬态响应是一串脉冲序列,脉冲彼此间隔为t=l/v的时间。同时也简单地讨论了换能器周围介质对脉冲响应的影响。从推导的结果可看出如何考虑声匹配层,以期获得良好的脉冲响应。更多还原

【Abstract】 Equations describing the transient response of thickness-mode piezoelectric -transducers for transmitters and receivers are derived using Laplace transform, Newton’s equation and piezoelectric equation. An example of delta finction excitation is given. In conclusion it is pointed out that the pulse response is a series of ultrasonic impulses separated by a time ι= 1/v when the electromechanic coupling factor kt is neglected The influence of the medium around the piezoelectric material in the transducer upon pulse response is briefly discussed. The result suggests how to construct an acoustic matching layer so that a good transient response can be obtained.Captions of figures:1. The sketchmap of thichness mode piezoelectric transducer; 2. Quantities of piezocrystal vibration; 3. The velocity wave driven by voltage pulse; 4. Two short pulse (bipolar) transducers; 5. Improving transient responce by using interlayer.更多还原