X-band filters utilizing AlN thin film bulk acoustic resonators

Motoaki Hara, Tsuyoshi Yokoyama, Masanori Ueda, Yoshio Satoh

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    23 Citations (Scopus)


    A filter with aluminum nitride thin-film bulk acoustic resonators (FBAR) for the X-band was developed. The FBAR has an air gap beneath the resonator to isolate acoustically from a substrate, and is extremely thin to operate in the X-band. The FBAR has two structural features - a sacrificial layer to make the air gap was very thin in order to prevent the resonator from cracking on the edge of the air gap, and a resonator was deformed to dome shape by stresses of the films to keep the air gap. The fabricated FBAR operated successfully with a keff of 6.40%, a resonance Q of 246, and anti-resonance Q of 462. The fabricated filter had a center frequency of 9.07 GHz, a fractional bandwidth of 3.1%, a minimum insertion loss of-1.7 dB, and an out-of-band rejection of -21 dB.

    Original languageEnglish
    Title of host publication2007 IEEE Ultrasonics Symposium Proceedings, IUS
    Number of pages4
    Publication statusPublished - 2007 Dec 1
    Event2007 IEEE Ultrasonics Symposium, IUS - New York, NY, United States
    Duration: 2007 Oct 282007 Oct 31

    Publication series

    NameProceedings - IEEE Ultrasonics Symposium
    ISSN (Print)1051-0117


    Other2007 IEEE Ultrasonics Symposium, IUS
    Country/TerritoryUnited States
    CityNew York, NY


    • Air gap
    • Aln
    • FBAR
    • Filter
    • X-band

    ASJC Scopus subject areas

    • Acoustics and Ultrasonics


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