Enhanced Sensitivity of a Surface Acoustic Wave Gyroscope

Abstract

In this paper, we present an optimal design and performance evaluation of a surface acoustic wave (SAW) gyroscope. It consists of a two-port SAW resonator (SAWR) and a SAW sensor (SAWS) structured using a delay line pattern. The SAW resonator provides a stable reference vibration and creates a standing wave, and the vibrating metallic dot array at antinodes of the standing wave induces the second SAW in the normal direction by the Coriolis force, and the SAW sensor is used to detect the secondary SAW. By using the coupling of modes (COM), the SAW resonator was simulated, and the effects of the design parameters on the frequency response of the device were investigated. Also, a theoretical analysis was performed to investigate the effect of metallic dots on the frequency response of the SAW device. The measured frequency response S21 of the fabricated 80 MHz two-port SAW resonator agrees well with the simulated result, that is, a low insertion loss (∼5 dB) and a single steep resonance peak were observed. In the gyroscopic experiments using a rate table, optimal metallic dot thickness was determined, and the sensitivity of the fabricated SAW gyroscope with an optimal metallic dot thickness of ∼350 nm was determined to be 3.2 µV deg-1 s-1.

FEM Simulation of a High-Performance 128°Y–X LiNbO3/SiO2/Si Functional Substrate for Surface Acoustic Wave Gyroscopes

“…Compared with traditional mechanical rotor gyroscopes and vibratory gyroscopes, the SAW gyroscope is a singlelayer planar structure with no moving parts and an elastic support structure with strong shock resistance and vibration resistance. In addition, SAW gyroscopes have the same advantages as SAW devices, such as small size, digital output, high sensitivity, and simple manufacturing [3][4][5]. The SAW gyroscopes that have been reported to date contain mainly standing wave and traveling wave modes.…”

Effect of Rare Earth Oxides on the Temperature Characteristics of BaTiO₃-Based Ceramics

“…Nb 5+ , Zr 4+ , and Ce 4+ ions were observed in the shell regions, but were absent in the core regions [5][6][7]. To obtain high-permittivity and flat-temperature coefficient of capacitance (TCC), BaTiO 3 have been modified by many oxides, such as Nb 2 O 5 -Co 3 O 4 [8], Nb 2 O 5 -ZnO [9], Bi 2 O 3 -TiO 2 [10], PbO-TiO 2, etc. In addition to these additives, rare earth oxides doping into BaTiO 3 ceramics could greatly change the microstructure, phase composition, density and properties of mechanics, physics, chemistry and sintering [11][12][13][14][15][16].…”

Development of a New Surface Acoustic Wave Based Gyroscope on a X-112°Y LiTaO3 Substrate

“…Varadan et al presented the design and performance evaluation of a 74.2 MHz microelectromechanical system-interdigital transducer (MEMS-IDT) SAW gyroscope with a similar structure [ 3 ]. Zhang and Wang present an optimal design of the SAW device using the coupling of modes, considering the effect of metallic dot thickness on sensor performance [ 4 ]. However, despite some reported important works on such SAW gyroscopes, they still suffer from low precision (submicron voltage detection) and poor temperature stability due to the use of large piezoelectric-coupling substrate materials like LiNbO 3 with high temperature coefficients.…”