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A Self-Oscillation Type SAW Microgyroscope Based on the Coriolis Effect of Progressive Waves

진행파의 코리올리효과를 이용한 자가발진형 표면탄성파 초소형 자이로스코프

  • Published : 2010.02.01

Abstract

An 80MHz surface acoustic wave (SAW)-based gyroscope utilizing a progressive wave was developed on a piezoelectric substrate. The developed sensor consists of two SAW oscillators in which one is used for sensing element and has metallic dots in the cavity between input and output IDTs. The other is used for a reference element. Coupling of mode (COM) modeling was conducted to determine the optimal device parameters prior to fabrication. According to the simulation results, the device was fabricated and then measured on a rate table. When the device was subjected to an angular rotation, oscillation frequency differences between the two oscillators were observed because of the Coriolis force acting on the metallic dots. Depending on the angular rate, the difference of the oscillation frequency was modulated. The obtained sensitivity was approximately 52.35 Hz/deg.s within the angular rate range of 0~1000 deg/s. The performances of devices with three IDT structures for two kinds of piezoelectric substrates were characterized. Good thermal stability was also observed during the evaluation process.

Keywords

Coriolis force;Progressive wave;Surface acoustic wave (SAW);Self-oscillation;Micro gyroscope

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