C-Axiszig-zag polarization inverted ScAlN multilayer for FBAR transformer rectifying antenna

Rei Karasawa, Takahiko Yanagitani

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


Energy harvesting from surrounding electromagnetic wave can satisfy the increasing demand of trillions of wireless sensors for IoT. RF energy harvesting is generally achieved by RF-DC conversion using a rectifying antenna (called rectenna). For weak RF signal, however, RF-DC conversion efficiency significantly decreases because weak RF signal cannot activate the diode in the rectenna. Therefore, in order to obtain high conversion efficiency for a weak signal, a Dickson charge pump[1] is generally used to increase the RF voltage. However, their low efficiency, poor impedance matching, and large size are the problem. In this study, to overcome this problem, we introduce the RF energy harvester consisting of a new type of polarization inverted FBAR transformer and rectenna. As shown in Fig.1 (a), RF input signal can be increased 7 times when 8 polarization inversion layered FBAR transformer is used. We previously reported various polarization inverted structure such as (0001)/(000-1) ScAlN films [2] and (-1-120)/(11-20) AlN films [3]. We here reports the eight layer of c-axis zig-zag polarization inverted ScAlN stack transformer resonator. [1] A. Parks, et al. Proc. IEEE WiSNET, (2013). [2] M. Suzuki, T. Yanagitani, and H. Odagawa, Appl. Phys. Lett. (2014) [3] M. Suzuki, T. Yanagitani, IUS 2011, 4C-2 (2011).

Original languageEnglish
Title of host publication2017 IEEE International Ultrasonics Symposium, IUS 2017
PublisherIEEE Computer Society
ISBN (Electronic)9781538633830
Publication statusPublished - 2017 Oct 31
Event2017 IEEE International Ultrasonics Symposium, IUS 2017 - Washington, United States
Duration: 2017 Sept 62017 Sept 9

Publication series

NameIEEE International Ultrasonics Symposium, IUS
ISSN (Print)1948-5719
ISSN (Electronic)1948-5727


Other2017 IEEE International Ultrasonics Symposium, IUS 2017
Country/TerritoryUnited States

ASJC Scopus subject areas

  • Acoustics and Ultrasonics


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