摘要 |
An acoustic wave device includes a piezoelectric substrate, IDT electrodes, temperature characteristic-improving layer, and frequency-adjusting layer arranged on the piezoelectric substrate in that order. The piezoelectric substrate has a negative temperature coefficient of frequency TCF. The temperature characteristic-improving layer is made of a material having a positive temperature coefficient of frequency TCF. The frequency-adjusting layer includes a glass thin-film having a velocity of transverse wave less than a velocity of transverse wave of the temperature characteristic-improving layer.
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