Surface acoustic wave filter

摘要

In a surface acoustic wave filter (1), an input-side IDT electrode (3) and an output-side IDT electrode (4) are arranged on a piezoelectric substrate (2) so as to be separated from each other in the propagation of a surface acoustic wave. The thickness of the IDT electrodes (3,4) is set so that the first coefficient of the velocity-dispersion has a negative value. <IMAGE> <IMAGE>