RF filter using boundary acoustic wave

Hajime Kando, Daisuke Yamamoto, Masakazu Mimura, Tetsuya Oda, Atushi Shimizu, Kazunori Shimoda, Eiichi Takata, Toshiyuki Fuyutsume, Ryuichi Kubo, Michio Kadota

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

33 Citations (Scopus)


Authors report a new structure of a shear horizontal (SH) type boundary acoustic wave for cellular phone applications. Such a structure composed of electrodes with a low shear wave velocity between two materials, namely, the SiO2 film/high density electrode/LiNbO3 substrate, is proposed. The unique feature of this structure is that it does not require a cavity on the substrate surface. The ladder filter and the longitudinal coupled multiple mode filter composed of this structure is reported. By changing the propagation angle of the acoustic wave, the electromechanical coupling factor k2 ranged from 0 to 16% as well as a normalized bandwidth of 0.67 to 1.85 fold as large as that of a 36-46° Y-X LiTaO3 leaky surface acoustic wave (LT-LSAW) filter. In addition, an excellent temperature coefficient of delay time (TCD=25 ppm/°C) and a large mutual coupling coefficient κ12 (=0.15) were also obtained. The newly developed RF filter using this structure was very small and thin.

Original languageEnglish
Title of host publication2006 IEEE International Ultrasonics Symposium, IUS
Number of pages4
Publication statusPublished - 2006 Dec 1
Event2006 IEEE International Ultrasonics Symposium, IUS - Vancouver, BC, Canada
Duration: 2006 Oct 32006 Oct 6

Publication series

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


Other2006 IEEE International Ultrasonics Symposium, IUS
CityVancouver, BC


  • Boundary acoustic wave
  • Electromechanical coupling factor adjustment
  • Power flow angle
  • RF filter
  • SH wave

ASJC Scopus subject areas

  • Acoustics and Ultrasonics


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