介绍了一种基于横向场激励模式的高频压电超声换能器及其设计、分析和制作过程。采用扩展的Christoffel-Bech-mann方法对LiNbO3、LiTaO3和PMN-33PT三种不同压电材料的a模式横向场压电耦合系数进行了计算,发现这三种材料中LiNbO3具有最大的LFE a模式压电耦合系数,为28%。采用具有最大压电耦合系数的X切LiNbO3设计并制作了基于横向场激励的高频超声换能器,并采用传统的Pulse-Echo方法测试了该超声换能器的中心频率和带宽。实验测得该LFE高频超声换能器的中心频率为34MHz,-6dB带宽为14.4%。从理论和实验上证明了横向场激励模式可以应用于高频超声换能器。
This paper presents the design,analysis and fabrication of Lateral Field Excited Piezoelectric Ultrasonic transducers. The Lateral field excitation coupling factors of three different kinds of piezoelectric materials (LiNbO3,LiTaO3,PMN-33PT) for a-mode have been calculated with the Extended Christoffel-Bechmann method. It was found that LiNbO3 had the maximum piezoelectric coupling factor of 28 %. The X-cut LiNbO3,which had the maximum piezoelectric coupling factor,was chosen for the design of a lateral field excited ultrasonic transducer. The center frequency and bandwidth of the ultrasonic transducer was tested using the traditional Pulse-Echo Method. The results showed that the center frequency of this lateral field excited ultrasonic transducer was 34MHz and the -6dB bandwidth was 14.4 %. Both theoretical and experimental works had demonstrated that lateral field excitation device could be used for the design of high frequency ultrasonic transducers.