[17p-C43-1~17] 1.6 Ultrasonics

4:00 PM - 4:15 PM JST(7:00 AM - 7:15 AM UTC)Presentation by Applicant for JSAP Young Scientists Presentation Award

[17p-C43-12] Double mode BAW filter (DMB) based on ScAlN using polarization inversion multilayer SMR

〇(M1)Momoka Matsumura^1,2, Saneyuki Shibata^1,2, Takahiko Yanagitani^1,2 (1.Waseda Univ., 2.ZAIKEN)

Keywords:

BAW filter,polarization inversion

gSurface acoustic wave (SAW) filters and bulk acoustic wave (BAW) filters are currently used as RF filters in smartphones. BAW filters are expected to be used for higher frequency bands (5 GHz~) in the future because of their higher power tolerance [1] compared to SAW filters. Two type of SAW filters currently in use are ladder-type SAW filters [2] and double mode type SAW (DMS) filters. Former uses a ladder-connection of SAW resonators, and latter uses acoustic coupling between SAW resonators [3]. On the other hand, for BAW filters, only ladder-type filters have been used. Although there are many reports on acoustic coupling type BAW filters such as stacked crystal filter (SCF) [4] and coupled resonator filter (CRF) [5], BAW filters using acoustic coupling like DMS filters have not been practical.
In this study, we newly propose double mode type BAW filters (DMB) consisting of polarization inverted multilayers. This configuration is more like DMS rather than CRF and SRF.