Ultra low loss acoustic wave devices for future communication systems

2014 Fiscal Year Final Research Report

• Project/Area Number: 25870042
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Nano/Microsystems; Electron device/Electronic equipment
• Research Institution: Tohoku University
• Principal Investigator: HARA Motoaki 東北大学, 工学(系)研究科(研究院), 准教授 (00417966)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: 圧電薄膜共振子 / 電極 / 薄膜

Outline of Final Research Achievements

A Thin Film Bulk Acoustic Resonator (FBAR) is a new class of acoustic devices fabricated on the substrate with thin film technologies. Ccharacteristics of the FBAR can be determined by the thickness or material of electrodes in comparison with bulk acoustic devices such as a quartz resonator. Conventionally, the FBAR is mainly applied to the wide band filter. So maximization of the coupling coefficient is a main issue in the FBAR design. Contrary, in this study, we newly focused on maximization of the Q factor for the application of the clock device with low phase noise.
To maximize the Q-factor, numerical program to calculate the resonance characteristic was originally developed based on the distributed constant equivalent circuit. Using this program, design parameters can be continuously tuned unlike conventional finite element method. Also, calculation time is much compressed, and calculation for various electrode material can be facilitated by combining with batch processing.

Free Research Field

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