Properties study of LiNbO_3 lateral field excited device working on thickness extension mode

• 作 者: 张志甜 张超 王文炎 马廷锋 刘岩 冯冠平
• 机 构: Department of Precision Instruments and Mechanology,Tsinghua University,Research Institute of Tsingh
• 出 处: Chinese Physics B
• 发表日期: 2010年09期
• 关键词: excited transducer excitation ultrasonic reaches analysed piezoelectric resonant

This paper investigates the properties of thickness extension mode excited by lateral electric field on LiNbO3 by using the extended Christoffel-Bechmann method. It finds that the lateral field excitation coupling factor for amode (quasi-extensional mode) reaches its maximum value of 28% on X-cut LiNbO3. The characteristics of a lateral field excitation device made of X-cut LiNbO3 have been investigated and the lateral field excitation device is used for the design of a high frequency ultrasonic transducer. The time and frequency domain pulse/echo response of the LiNbO3 lateral field excitation ultrasonic transducer is analysed with the modified Krimholtz-Leedom-Matthae model and tested using traditional pulse/echo method. A LiNbO3 lateral field excitation ultrasonic transducer with the centre frequency of 33.44 MHz and the -6 dB bandwidth of 33.8% is acquired, which is in good agreement with the results of the Krimholtz-Leedom-Matthae model. Further analysis suggests that the LiNbO3 lateral field excitation device has great potential in the design of broadband high frequency ultrasonic transducers.

This paper investigates the properties of thickness extension mode excited by lateral electric field on LiNbO3 by using the extended Christoffel-Bechmann method. It finds that the lateral field excitation coupling factor for amode (quasi-extensional mode) reaches its maximum value of 28% on X-cut LiNbO3. The characteristics of a lateral field excitation device made of X-cut LiNbO3 have been investigated and the lateral field excitation device is used for the design of a high frequency ultrasonic transducer. The time and frequency domain pulse / echo response of the LiNbO3 lateral field excitation ultrasonic transducer is analyzed with the modified Krimholtz-Leedom-Matthae model and tested using the traditional pulse / echo method. A LiNbO3 lateral field excitation ultrasonic transducer with the center frequency of 33.44 MHz and the -6 dB bandwidth of 33.8% is acquired, which is in good agreement with the results of the Krimholtz-Leedom-Matthae model. Further analysis suggests that the LiNbO3 l ateral field excitation device has great potential in the design of broadband high frequency ultrasonic transducers.