Surface acoustic wave devide

摘要

A surface acoustic wave device includes a piezoelectric substrate and plural IDTs for sending and receiving SAW mounted on the substrate. At least one of the IDTs includes a positive electrode including plural positive split electrodes (PSEs) and a negative electrode including plural negative split electrodes (NSEs). The PSEs and NSEs are arranged alternately. Each of the PSEs and NSEs has a pair of electrode fingers. Two electrode fingers of each of the split electrodes are different in width in a direction in which a SAW is excited. An angle a determined by a direction transverse to the electrode fingers from one of the two electrode fingers having a smaller reflection factor toward the other one having a larger reflection factor and a direction in which the SAW excited by the IDT including the split electrodes travels to one of the IDTs for receiving the SAW is equal to or larger than 0 DEG and smaller than 90 DEG , i.e., 0</= alpha <90.