Patent ID: 7368847

Claim:
A surface acoustic wave device, comprising: a three-dimensional substrate having a surface, which includes at least a part of an annular curved surface formed with a continuous curved surface on which a surface acoustic wave propagates; and an electro-acoustic transducing element, which excites the surface acoustic wave along the surface, which propagates the surface acoustic wave along the surface, and which receives the surface acoustic wave propagating along the surface, the device characterized in that the three-dimensional substrate is made of a LiTaO 3 crystal, and, along the surface of the three-dimensional substrate, the electroacoustic transducing element excites the surface acoustic wave to propagate along a line of intersection between a crystal face of the LiTaO 3 crystal and the surface thereof, a normal line of the crystal face being a crystal axis specified by rotating a +Y axis that is a crystal axis of the LiTaO 3 crystal by 45° in a -Z direction with an X axis being a rotational center, and the line of intersection defined as an outermost circumferential line.