| 摘要 |
PURPOSE:To improve the characteristic coefficient of surface acoustic waves, by using Rayleigh waves which are propagated in direction parallel with the X axis on the face of the X axis or in a direction perpendicular to the A axis on a specified cut face on the cut face perpendicular to the Z axis of Ba2Si2TiO3 single crystal. CONSTITUTION:A substrate 1 is formed by cutting Ba2Si2TiO3 single crystal along crystal axial coordinates shown in figure, and surface acoustic waves (SAW) are propagated in the direction of an arrow R. Waves SAW ar propagated on the cut face perpendicular to the Z axis. They are propagated in a direction parallel with the X axis on the cut face including the X axis. Otherwise, they are propagated in a direction perpendicular to the X axis on the cut face where the X axis is included and an angle mu between the Z axis and a direction perpendicular to the cut face is within the range incidated by expression. By using these SAW, a good surface acoustic wave device of >=0.6% electromechanical coupling coefficient, <=70ppm/ deg.C delay time temperature coefficient, and <=0.4 deg. power flow angle is obtained. |
