新型声表面波式小波变换器件插入损耗的研究  

Study of Insertion Loss for Wavelet Transform Element of New SAW Type

作　　者：卢文科[1] 朱长纯[2] 刘君华[2] 方建安[1] 文常保[2] 

机构地区：[1]东华大学信息科学与技术学院,上海200051 [2]西安交通大学电子与信息工程学院,陕西西安710049

出　　处：《电子学报》2006年第2期371-373,共3页Acta Electronica Sinica

基　　金：国家自然科学基金(No.6017020;No.60476037);863项目(No.2001AA313090);博士点基金(No.20020698014)

摘　　要：小波式叉指换能器使用机电耦合系数比较大的基片(如YZ-L iNbO3基片)时,其频率特性曲线不光滑,但插入损耗小;小波式叉指换能器使用机电耦合系数比较小的基片(如X 112°Y-L iTaO3基片)时,其频率特性曲线光滑,但插入损耗大.声表面波器件的指条对数N越少,其带宽Δf/f越大,插入损耗越大,所以,指条对数N要取的合适,不宜过少.在声表面波式小波变换器件中,发射叉指换能器的条对数N取57,接收叉指换能器的指条对数是57的四分之一到三分之一之间.If the substrate of larger electromechanical coupling coefficient （such as YZ-LiNbO3 substrate） is used for wavelet type of interdigital transducer （IDT）, its frequency characteristic curve is not smooth, but its insertion loss is smaller. If the substrate of smaller electromechanical coupling coefficient （such as X 112°Y-LiTaO3 substrate） is used for wavelet type of IDT, its frequency characteristic curve is smooth, but its insertion loss is larger. The less the finger pairs N of surface acoustic wave （SAW） element, the larger its bandwidth △f/f, and the larger its insertion loss, so the finger pairs N is appropriately taken, and is not too small. In wavelet transform element of SAW type, the finger pairs N of the transmitting IDT is 57 ,the finger pairs N of the receiving IDT is between one-fourth of 57 and one-third of 57.

关 键 词：声表面波 小波变换器件 插入损耗 又指换能器 

分 类 号：O426.9[理学—声学] O29[理学—物理]