PURPOSE: To provide a desired characteristic by unifying stress distribution formed by the cross part if electrode fingers by widening the arrangement intervals of paired electrode fingers at the electrode finger cross part along a direction where the the electrode fingers are extended.
CONSTITUTION: An interdigital electrode 2 provided with a pair of electrode fingers 3a and 3b and a pair of common electrodes 2a and 2b is formed on a piezoelectric substrate 1. Concerning the electrode fingers 3a and 3b, the almost top of the faced electrode fingers 3b and 3a sides is constituted by providing inclined parts 6b and 6a, and the interval of the electrode fingers 3a and 3b is gradually widened toward the terminal part of an electrode finger cross part 4. In this case, an electric field to be generated at the electrode finger cross part 4 is almost uniform electric field intensity distribution inside the electrode finger cross part 4. Therefore, the distortion of the piezoelectric substrate 1 is made uniform as well, and the degradation of a frequency characteristic or a group delay characteristic caused by the disturbance of stress distribution can be suppressed.
SHIBA TAKASHI
YUHARA AKITSUNA
