| 摘要 |
PURPOSE: An FBAR(Film Bulk Acoustic Resonator) filter duplexer is provided to reduce a coupling effect generated between plural FBARs and reflective waves generated from piezoelectric layers by forming an attenuation portion around or inserting acoustic absorption material between the FBARs. CONSTITUTION: An FBAR filter duplexer includes a plurality of FBARs(51,52,53,54). The FBARs are formed with a semiconductor substrate(50), a plurality of piezoelectric layers(51a,52a,53a,54a), a plurality of upper electrodes(51b,52b,53b,54b), and a plurality of lower electrodes(51c,52c,53c,54c). The piezoelectric layers are formed on the semiconductor substrate to generate a resonant characteristic. The upper and the lower electrodes are formed on an upper portion and a lower portion of the piezoelectric layers. The FBARs include a plurality of attenuation portions(51d,52d,53d,54d) which are formed around the FBARs in order to attenuate electromagnetic waves generated from the piezoelectric layers and prevent a coupling effect generated between the FBARs. |
