Patent ID: 6879086

Claim:
A surface acoustic wave apparatus comprising: a piezoelectric substrate; at least one longitudinally-coupled-resonator surface acoustic wave filter including at least three interdigital electrode transducers provided on said piezoelectric substrate along the propagation direction of surface acoustic waves; and at least one surface acoustic wave resonator that is connected in series to at least two of the at least three interdigital electrode transducers of the longitudinally-coupled-resonator surface acoustic wave filter; wherein the parasitic capacitance between the longitudinally-coupled-resonator surface acoustic wave filter and the surface acoustic wave resonator is set to about 6.5×10 2 /f 0 [pF] or less, where f 0 represents the center frequency, in megahertz, within the pass band of the longitudinally-coupled-resonator surface acoustic wave filter.