SURFACE ACOUSTIC WAVE APPARATUS

摘要

PROBLEM TO BE SOLVED: To realize a surface acoustic wave resonator which does not have ripples in the impedance characteristics. SOLUTION: The surface acoustic wave resonator comprises IDT electrodes which is weighted in an electrode finger-crossing width and formed on a piezoelectric substrate, and a bus bar of an inner periphery provided in non-parallel with the direction of the group velocity of surface acoustic waves to be excited by the IDT electrodes. In this resonator, electrode fingers of a reflector and electrode fingers of an exciter are deviated in a group speed direction of the surface acoustic wave, or a distance between an outer periphery of the excitation section and the inner periphery of the bus bar is limited to a certain length or smaller.