Saw Filter Comprising a Broadband Band-Stop Filter

摘要

A band-stop filter is described herein. The band-stop filter includes a piezoelectric substrate and a plurality of surface wave element (SAW) impedance elements on the substrate. The band-stop filter also includes at least one series branch comprising at least one series resonator having a finger period, and a plurality of parallel branches connected electrically in parallel with the series branch, each parallel branch including at least one parallel impedance element comprising an interdigital transducer and having a finger period. The average finger period of the at least one series resonator is greater than the average finger period of the at least one parallel impedance element.