Acoustic wave devices, acoustic wave device packages, multiplexers, high-frequency front-end circuits and communication devices

摘要

An acoustic wave device in which the frequency position of a higher-order mode propagating in a support substrate made of silicon is unlikely to become non-uniform. A support substrate 2 made of silicon, a piezoelectric body 4 provided directly or indirectly on the support substrate 2 and having a pair of opposite main surfaces, and on at least one main surface of the piezoelectric body 4 on to V 1, V 2, V 3 of V 1 in the x, derived from direct or may indirectly provided with the electrode that the wavelength determined by the pitch comprises a λ of the IDT electrode (5), following formula (2) The acoustic wave device (1) in which the sound velocity V Si =(V 1 ) 1/2 of the bulk wave propagating in the support substrate (2) is 5500 m/sec or more, which is defined by Ax 3 +Bx 2 +Cx+D=0 … Equation (2)