| 摘要 |
PURPOSE:To obtain a lithium tantalate medium substrate with excellent temperature coefficient and to attain a surface acoustic wave element having a large coupling factor by forming a reed screen electrode formed with two comb- tooth electrodes meshed with each other. CONSTITUTION:The lithium tantalate substrate 1 having 0 deg. and 130 deg. of Euler angles phi and theta respectively forms an end face reflecting type pizoelectric shear wave resonator. A surface-shear wave is generated by the reed screen electrode 2, reflected on free end faces 3, 4 to offer a resonance characteristic. The surface-shear wave is changed in a direction in parallel with fingers 2c, 2d of the comb-tooth electrodes 2a, 2b of the reed screen electrode 2 and propagated in a direction at a right angle thereto, then the mode is not converted into other modes at the free end faces 3, 4 and the wave is refledted while being kept to be the surface-shear wave. |
