| 摘要 |
Provided are a surface acoustic wave device suitable to mass production and showing good surface acoustic wave propagation performance, and an environmental difference detecting apparatus using the device. The device comprises: a three-dimensional substrate (12) having a surface, which includes at least a part of an annular curved surface formed with a continuous curved surface enabling to propagate a surface acoustic wave; and an electro-acoustic transducing element (14), which excites the surface acoustic wave along the surface, which propagates the surface acoustic wave along the surface, and which enables to receive the surface acoustic wave propagating along the surface, the device characterized in that the substrate is made of a Li 2 B 4 O 7 crystal, a Bi 12 SiO 20 crystal, a LiNbO 3 crystal, a LiTaO 3 crystal, or a quartz crystal, and along a surface of the substrate, the element propagates the surface acoustic wave along a line of intersection between a crystal face of the crystal and the surface, and the line of intersection is defined as an outermost circumferential line (12b) of the surface. The environmental difference detecting apparatus compares surface acoustic wave reception signals of electro-acoustic transducing elements in a plurality of propagating surface zones of the surface acoustic wave device with each other, and detects an environmental difference in space portions with which the propagating surface zones come into contact.
|
