中文摘要：

提出了一种利用聚偏二氟乙烯（PVDF）压电薄膜层叠的组合结构方案设计超声换能器，用以解决柔性薄膜超声换能器输入／输出信号增益低的问题；并通过理论推导及数学软件仿真给出了该结构换能器的幅频特性。利用仿真结果可估算出层叠式结构超声探头的增益、谐振频率和通频带与PVDF薄膜厚度及薄膜层数之间的对应关系。这对于缩短高频超声探头的设计周期，降低开发成本，提高探头转换增益及检测灵敏度都具有重要意义。

英文摘要：

A layer-built ultrasonic transducer based on PVDF piezoelectric film is proposed to solve one of the key technical issues concerning the low input/output gain in the piezoelectric film ultrasonic transducer. The ampli- tude frequency characteristics of ultrasonic transducer is educed by theory deduction and software simulation. More- over the dependence of its gain, resonance frequency and bandwidth on the thickness and the layer number of the film could be reasonably caculated by the simulation result, which is very important for shortening the design cycle, reducing the product cost of ultrasonic transducer,and improving its conversion gain and sensitivity.