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本文提出了一种带有声阻抗匹配层的宽带聚合物超声换能器,其中聚苯乙烯或聚丙烯匹配层粘在偏二氟乙烯和三氟乙烯共聚物(P(VDF—TrFE))压电薄膜的正表面。匹配层厚度为λ/4,对于在水中获得宽带频率响应和尖锐的脉冲响应最为有效,分析的结果和实验结果都证明,换能器加匹配层后,其深度分辨力比一般P(VDF—TrFE)换能器高1.7倍,而灵敏度没有任何降低。用这种新型换能器获得的医疗超声成象表明了它的实用性。
In this paper, a broadband polymer ultrasonic transducer with an acoustic impedance matching layer is proposed, in which a polystyrene or polypropylene matching layer is stuck on a piezoelectric (P (VDF-TrFE)) film of a vinylidene fluoride and trifluoroethylene copolymer The front surface of the film. The thickness of the matching layer is λ / 4, which is most effective for obtaining broadband frequency response and sharp impulse response in water. The analysis results and the experimental results show that the depth resolution of the transducer after matching layer is higher than that of general P (VDF- TrFE) transducer 1.7 times higher without any reduction in sensitivity. Medical ultrasound images obtained with this new transducer demonstrate its usefulness.