SURFACE ACOUSTIC WAVE RESONATOR, AND SURFACE ACOUSTIC WAVE FILTER AND ANTENNA DUPLEXER IN WHICH THE SURFACE ACOUSTIC WAVE RESONATOR IS USED

摘要

The present invention provides a surface acoustic wave resonator capable of improving the leak of a surface acoustic wave in the transverse direction and reducing the spurious and having superior characteristics. In a surface acoustic wave filter according to the present invention, an interdigital transducer electrode and reflector electrodes are formed on a piezoelectric substrate, and a SiO₂ thin film is further formed thereon. The interdigital transducer electrode includes a bus-bar electrode region, a dummy electrode region and a finger overlap region, and the SiO₂ thin film is removed from upper sections of the bus-bar electrode regions in the interdigital transducer electrode.