Surface wave resonator having single component including a plurality of resonant units

摘要

An end face reflection type surface wave resonator utilizing SH type surface waves capable of providing a plurality of resonance characteristics is formed as a single element. In the surface wave resonator, surface waves are reflected between two opposite end faces of a piezoelectric substrate. The surface wave resonator has IDTs that form first and second resonant units. The distance L between the two end faces is selected to be within a range expressed by ( lambda 1/2)xN1+/-( lambda 1/20) (N1 is an integral number) where lambda 1 represents the wavelength of a surface wave excited by the first resonant unit. The distance L is chosen to be out of a range expressed by ( lambda 2/2)xN2+/-( lambda 1/20) (N2 is an integral number) where lambda 2 represents the wavelength of a surface wave excited by the second resonant unit.