Surface acoustic wave filter

摘要

A longitudinally-coupled resonator mode SAW filter portion having at least two interdigital transducers (IDTs) is disposed on a piezoelectric substrate. At least one SAW resonator is electrically connected in parallel with the SAW filter portion such that the at least one SAW resonator is disposed between an input terminal or an output terminal and the SAW filter portion. The resonance point of the SAW resonator is disposed in the pass band of the SAW filter portion.