Patent ID: 9190981
Filing Date: 2015-11-17
Classification: H03H

Abstract:
1. An elastic wave device comprising: a supporting substrate; a medium layer stacked on the supporting substrate; a piezoelectric body which is stacked on the medium layer and in which a bulk wave propagates; and an IDT electrode disposed on a surface of the piezoelectric body; wherein the medium layer includes a low-velocity medium in which a propagation velocity of a same bulk wave as that which is a main component of an elastic wave propagating in the piezoelectric body is lower than an acoustic velocity of an elastic wave propagating in the piezoelectric body, and a high-velocity medium in which the propagation velocity of the same bulk wave as that which is the main component of the elastic wave propagating in the piezoelectric body is higher than the acoustic velocity of the elastic wave propagating in the piezoelectric body; and the medium layer is configured such that an acoustic velocity of a main vibration mode in the elastic wave device including the medium layer satisfies a relationship V