SURFACE ACOUSTIC WAVE ELEMENT

PURPOSE:To simplify the pattern constitution of interdigital electrodes, and to provide unidirectivity. CONSTITUTION:An interdigital transducer is constituted by forming the interdigital electrodes on the surface of a piezoelectric substrate. In a piezoelectric substrate 1, protruding portions 1a having inclined faces in the same direction are provided at prescribed intervals toward the propagating direction (shown by an arrow) of a surface acoustic wave, the electrode films of interdigital electrodes 2a and 2b are formed on the protruding portions by vapor deposition or hot etching, and the excitement of an exciting power source 3 is allowed to have directivity, so that the surface acoustic wave can be unidirectionally propagated. The pattern constitution of the interdigital electrodes is made equivalent to that of a general bidirectional transducer.