Characteristics of Multilayer Ultrasonic Piezoelectric Transducers with an Inversion Layer

• Main Authors: Hao-Hsiang Hung, 洪浩翔
• Other Authors: Wen-Jeng Hsueh
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/61123219446006808320

碩士 === 國立臺灣大學 === 工程科學及海洋工程學研究所 === 95 === Recently, ultrasonic piezoelectric transducer with an inversion layer has been gaining interest in the development of broadband transducer. In this research we present an analytical model for the analysis of double-layer ultrasonic piezoelectric transducers with an inversion layer. We also analyzed electric input impedance and efficiency of transducers by transfer matrix method. The design of transducers including single and double-layer piezoelectric films with an inversion layer, backing material, and matching layer is presented. Effects of inversion layer ratio and characteristic impedance of backing material on the performace are studied. Whether transducer bandwidth and efficiency have matching layers or not we make sure of those effects. Finally, numerical calculations of multilayer ultrasonic piezoelectric transducers by transfer matrix method is examined to understand the characteristics of the transducers working in dual-frequency operation mode, which has been used in harmonic image or broadband characteristic of most ultrasonic applications.