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为使声表面波滤波器应用领域更加广泛,需要解决下面两个问题;(i)频率可以微调。(ii)具有良好的温度特性等。本报告中,为了同时解决上述两个问题,取通用的石英 ST 切割基片为例,对声表面波相位速度和频率温度特性跟切割角度、面内旋转角以及构成换能器的电极膜之间的关系,进行了理论与实验方面的详细探讨。结果表明,相(?)速度与面内旋转角的平方成正比例地增加。因此,我们将声表面波的传播方向偏离 X轴修正±4°左右,修正后并不破坏它的温度特性,还可以在+1000PPm 范围内进行频率调整。此外,由于电极膜的负载效应,使相位速度减小以及频率温度特性的拐点温度朝低温端移动。综上所述,我们可获得既考虑了石英基片的切割角和旋转角,同时还考虑了电极膜影响的声表面波滤波器的设计参数。
To make surface acoustic wave filter applications more widespread, the following two issues need to be addressed; (i) The frequency can be fine-tuned. (ii) have good temperature characteristics and the like. In this report, in order to solve the above two problems at the same time, take a common quartz ST cutting substrate as an example, the surface acoustic wave phase speed and frequency temperature characteristics with the cutting angle, in-plane rotation angle and the electrode film constituting the transducer Between the relationship between the theoretical and experimental aspects of a detailed discussion. The results show that the phase (?) Velocity increases in proportion to the square of the in-plane rotation angle. Therefore, we will SAW propagation direction deviation ± 4 ° from the X-axis correction does not undermine its temperature characteristics, but also in the range of + 1000PPm frequency adjustment. In addition, due to the load effect of the electrode film, the phase speed is reduced and the inflection point temperature of the frequency temperature characteristic is shifted toward the low temperature side. In summary, we have obtained the design parameters of the SAW filter, which takes into account not only the cutting angle and the rotation angle of the quartz substrate, but also the influence of the electrode film.