Lewin P A, Schafer M E
Dept. of Electr. and Comput. Eng., Drexel Univ., Philadelphia, PA.
IEEE Trans Ultrason Ferroelectr Freq Control. 1988;35(2):175-85. doi: 10.1109/58.4168.
The design of a wideband acoustic source made of the piezoelectric polymer polyvinylidine fluoride (PVDF) is described. The source was developed for the characterization and absolute calibration of ultrasonic hydrophone probes. Construction details are described and performance characteristics of the wideband PVDF transmitter, including its transmitting voltage response and directivity patterns, are compared with theoretical predictions in the frequency range up to 40 MHz. The Krimholtz-Leedom-Mattaei (KLM) model was used to examine the influence of the PVDF polymer film thickness, the backing acoustic impedance, the cable length, and the electrical source resistance on overall transmit transfer characteristics. A comparison is made with traditional piezoelectric ceramic acoustic sources, and it is shown that piezopolymer transmitters exhibit some improved properties and are well suited for certain ultrasound dosimetry applications. In particular, the polymer sources have been found useful in measurements based on swept-frequency excitation. Those measurements allow characterization of transmitters and receivers to be performed as a virtually continuous function of frequency.
本文描述了一种由压电聚合物聚偏二氟乙烯（PVDF）制成的宽带声源的设计。该声源是为超声水听器探头的特性表征和绝对校准而开发的。文中介绍了其结构细节，并将宽带PVDF发射器的性能特性，包括其发射电压响应和指向性图，与高达40MHz频率范围内的理论预测进行了比较。使用Krimholtz-Leedom-Mattaei（KLM）模型研究了PVDF聚合物薄膜厚度、背衬声阻抗、电缆长度和电源电阻对整体发射传输特性的影响。与传统的压电陶瓷声源进行了比较，结果表明压电聚合物发射器具有一些改进的特性，非常适合某些超声剂量学应用。特别是，已发现聚合物声源在基于扫频激励的测量中很有用。这些测量允许将发射器和接收器的特性表征作为频率的几乎连续函数来执行。
