Acoustic surface wave element
    3.
    发明授权
    Acoustic surface wave element 失效
    声表面波元件

    公开(公告)号:US4978879A

    公开(公告)日:1990-12-18

    申请号:US384829

    申请日:1989-07-25

    IPC分类号: H03H9/02

    CPC分类号: H03H9/02834 H03H9/02559

    摘要: An acoustic surface wave element having an oscillation frequency stable against temperature changes, and a wide range of oscillation frequency adjustment, is provided by an acoustic surface wave element comprising: a substrate of a 36.degree. rotated Y-cut single crystal lithium tantalate having X, Y and Z crystal axes and a top surface and side walls; electrodes formed on the top surface of the substrate such that an acoustic surface wave is propagated in a direction of the X-axis of the substrate and an oscillation of the acoustic surface wave occurs at a predetermined frequency, the electrodes having a thickness equal to 1 to 4% of a wavelength of the acoustic surface wave at the oscillation; and a plasma CVD-deposited layer of silicon dioxide covering the electrodes and the substrate, the silicon dioxide layer having a refractive index of 1.445 to 1.486 and a thickness equal to 16 to 26% of the wavelength of the acoustic surface wave at the oscillation.

    Surface acoustic wave filter with larger driving electrode areas in some
parallel resonators, and packaging thereof
    4.
    发明授权
    Surface acoustic wave filter with larger driving electrode areas in some parallel resonators, and packaging thereof 失效
    在一些并联谐振器中具有较大驱动电极面积的表面声波滤波器及其包装

    公开(公告)号:US5914646A

    公开(公告)日:1999-06-22

    申请号:US834768

    申请日:1997-04-03

    申请人: Kazushi Hashimoto

    发明人: Kazushi Hashimoto

    CPC分类号: H03H9/1071 H03H9/6483

    摘要: A surface acoustic wave filter element is formed by replacing with a single parallel resonator having a driving electrode whose area is equal to the sum total of the areas of driving electrodes of a plurality of consecutive parallel resonators arranged in a ladder shape, together with serial resonators, for structuring a surface acoustic wave resonator. Also, in a surface acoustic wave filter formed by packaging the surface acoustic wave filter element, ground electrodes of the parallel resonators of the filter element are electrically insulated from each other and are connected to different electrode pads for grounding.

    摘要翻译: 表面声波滤波器元件通过用具有驱动电极的单个并联谐振器代替,该驱动电极的面积等于以梯形形式布置的多个连续并联谐振器的驱动电极的面积的总和等于串联谐振器 ,用于构造表面声波谐振器。 此外,在通过封装声表面波滤波器元件形成的表面声波滤波器中,滤波器元件的并联谐振器的接地电极彼此电绝缘并且连接到不同的接地用电极焊盘。