Fay B, Ludwig G, Lankjaer C, Lewin P A
Physikalisch-Technische Bundesanstalt, Braunschweig, Germany.
Ultrasound Med Biol. 1994;20(4):361-6. doi: 10.1016/0301-5629(94)90004-3.
This paper examines the factors governing the frequency response of ultrasonic polyvinylidene fluoride (PVDF) polymer needle-type hydrophones, in particular the sensitivity variations in the lower frequency range of 1-6 MHz. A theoretical model was used to analyze the influence of the hydrophone's diameter, the metal electrodes, thickness, PVDF material properties, the adhesive layer acoustical characteristics and the backing material, on the frequency response of the hydrophone. The results of the theoretical modelling differ by less than +/- 0.5 dB from those obtained experimentally from the reciprocity calibration in the frequency range 1-20 MHz. It is shown that the needle hydrophone's diameter and backing material are the main reasons for the sensitivity variations observed in the frequency range below 6 MHz.
本文研究了影响超声聚偏二氟乙烯（PVDF）聚合物针型水听器频率响应的因素，特别是在1-6 MHz低频范围内的灵敏度变化。采用理论模型分析了水听器直径、金属电极、厚度、PVDF材料特性、粘合层声学特性和背衬材料对水听器频率响应的影响。理论建模结果与在1-20 MHz频率范围内通过互易校准实验获得的结果相差不到±0.5 dB。结果表明，针型水听器的直径和背衬材料是在6 MHz以下频率范围内观察到灵敏度变化的主要原因。
