Bulk acoustic wave filter and method for eliminating unwanted side passbands

摘要

A bulk acoustic wave (BAW) filter ( 40 ) is fabricated from thin film bulk acoustic wave resonators and a method eliminates unwanted side passbands. This BAW filter comprises a substrate ( 14 ) a resonator section ( 11 ) and an acoustic mirror section ( 12 ). Further it comprises a detuning component ( 31 ) positioned in the resonator section ( 11 ) to provide precise passband characteristics and an additional detuning component ( 41 ) in the acoustic mirror section ( 12 ) to suppress unwanted side-passband characteristics.