SURFACE ACOUSTIC WAVE FILTER AND ANTENNA DUPLEXER EMPLOYING THE SAME

摘要

PROBLEM TO BE SOLVED: To easily ensure the attenuation band characteristic of a surface acoustic wave filter by connecting an inductive element to a surface acoustic wave resonator. SOLUTION: The surface acoustic wave filter with a prescribed pass band and a prescribed attenuation band is characterized in that the surface acoustic wave filter comprises a piezoelectric substrate and a plurality of one-terminal pair surface acoustic wave resonators formed on the piezoelectric substrate and an inductive element is connected in parallel with at least one surface acoustic wave resonator connected in series between an input terminal and an output terminal, and varying the inductive inductance can easily ensure a desired attenuation band characteristic.