Analysis of longitudinal leaky surface acoustic waves on quartz thin plate bonded to similar-material substrate

Abstract

The propagation and resonance properties of longitudinal leaky surface acoustic waves (LLSAWs) on bonded structures consisting of a quartz (Qz) thin plate and a Qz support substrate with different Euler angles were investigated theoretically. By using both an X-cut Qz thin plate and a Qz support substrate with optimal Euler angles, we obtained LLSAWs with a larger coupling factor, a smaller attenuation, and a lower temperature coefficient of frequency than those on a single Qz substrate. Furthermore, from the resonance properties simulated by the finite element method, the bonded structures were found to exhibit a large admittance ratio and a high quality factor, which could not be obtained when using a single Qz substrate; the bandwidth however was as small as 0.016-0.086%.

Analysis of longitudinal leaky surface acoustic waves on bonded structures consisting of similar and dissimilar materials

“…First, we calculated the LLSAW propagation properties on a structure consisting of an LT thin plate bonded to X176.5°Y-Qz/X41°Y-Qz, 25) which exhibits high Q LLSAW resonance properties. We searched for the optimal propagation angle at which the attenuation is reduced by varying the propagation angle of LT on X176.5°Y-Qz/X41°Y -Qz.…”

“…Unfortunately, FBW is small, less than 0.15%. 25) To obtain a larger FBW, we have investigated the propagation and resonance properties of LLSAWs on a structure consisting of LT thin plates bonded to a Qz similar-material bonded structure. We have found the conditions under which small attenuation and large resonance responses can be obtained.…”

Ultrasensitive wireless quartz crystal microbalance bio/gas sensors

“…Its crystallographic symmetry belongs to the 32-point group (trigonal system), exhibiting six independent elastic constants, two independent piezoelectric constants, and two independent dielectric constants. Thanks to these important properties, quartz has been used as a substrate in many resonators for communication devices, [1][2][3] biosensors, [4][5][6] gas sensors, [7][8][9][10] viscosity sensors, [11][12][13] and stress sensors. 14) AT-cut quartz resonators have been most commonly used for sensing applications because their through-thickness shear-resonance frequency shows extremely high temperature stability near RT.…”

Analysis of longitudinal leaky surface acoustic waves on piezoelectric thin plates bonded to diamond substrate

“…The research and development of SAW propagation modes and piezoelectric materials for high-performance SAW devices have been actively conducted in Japan and overseas. [1][2][3][4][5][6][7][8][9][10][11][12][13] In particular, 5 GHz bands, called the Sub-6 band in 5G communication systems, are approximately 1.5-2 times higher than those of 4G communication systems. Hence, there is a significant demand for higher frequencies in SAW filters.…”