Patent ID: 7863801
Filing Date: 2011-01-04
Classification: H03H

Abstract:
1. An acoustic wave device comprising: a piezoelectric substrate; interdigital transducer electrodes disposed on the piezoelectric substrate; a temperature characteristic-improving layer extending over the piezoelectric substrate and the interdigital transducer electrodes; and a frequency-adjusting layer disposed on the temperature characteristic-improving layer; wherein the piezoelectric substrate is made of a piezoelectric material having 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; and the frequency-adjusting layer includes a glass thin-film having a velocity of transverse wave that is less than a velocity of transverse wave of the temperature characteristic-improving layer and having a coefficient of linear expansion that is less than a coefficient of linear expansion of the piezoelectric substrate.