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

Self Cite

The rapid development of mobile communications requires high performance surface acoustic wave (SAW) filters. ScAlN film SAW resonators have a high coupling factor (K2) and high phase velocity, enabling them to function as effective SAW filters. We theoretically investigated high-order mode Rayleigh SAWs (RSAWs) on single-layered or polarity inverted two-layered ScAlN film/AlN or BN substrate structures to find the optimal structure to achieve a higher K2 and higher frequency. The K2 and phase velocity for the single-layered ScAlN film/BN substrate structure were higher than those the corresponding AlN substrate structure. The K2 was enhanced in the polarity inverted ScAlN film/AlN or BN substrate structure. Finite element method analysis revealed that the effective coupling factor Keff2 for the 2nd to 4th mode RSAWs on polarity inverted multilayered ScAlN films was enhanced by setting the boundary of the polarity inverted structure at the all positions where the particle displacements were concentrated.

Section: Fem Analysismentioning

confidence: 99%

Enhancement of coupling factor in 0th to 4th mode Rayleigh surface acoustic waves on polarity inverted multilayered ScAlN film/AlN and BN substrates

Takano

Suzuki

Kakio

2022

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“…22) We also theoretically found that the resonance properties of LSAWs on similar-material bonded substrates consisting of a Qz thin plate and a Qz support substrate with different Euler angles are larger than those on a single substrate. 23) We theoretically investigated the propagation and resonance properties of LLSAWs on bonded structures comprising a Qz thin plate and a Qz support substrate, and found the conditions optimal for obtaining small attenuation and large resonance properties. 24) In this study, those properties were investigated in more detail using an analytical solution and a finite element method (FEM).…”

Section: Introductionmentioning

confidence: 99%

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

Fujii

Fujimaki

Suzuki

et al. 2022

Self Cite

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%.

“…We have developed a ball surface acoustic wave (SAW) sensor, [9][10][11] as an application of piezoelectric devices [12][13][14][15] such as a planar SAW sensor 16) and quartz crystal microbalances. 17,18) Using the ball SAW sensor as a detector, we developed a portable ball SAW GC.…”

Section: Introductionmentioning

confidence: 99%

Development of ball surface acoustic wave gas chromatograph for environmental monitoring in spacecraft and its application on the ground

Iwaya

Akao

Yamanaka

et al. 2022

For on-site analysis of surface materials on the moon, planets, and small bodies and for the monitoring of air quality in crewed spacecraft, we have developed a portable gas chromatograph (GC) equipped with a ball surface acoustic wave (SAW) sensor. In this study, we fabricated a 10 cm cube GC that implements the forward flush method using two metal micro-electro-mechanical-system (MEMS) columns coated with different stationary phases in microchannels fabricated by wet etching and diffusion bonding of stainless-steel plates. Using this GC, we succeeded in analyzing 10 kinds of gas within 10 min. In addition, for the application of the ball SAW GC on the ground, we also developed a palm-sized GC with a single metal capillary column and used it in the analysis of the headspace gas of sake. We showed that the ratio of peak areas differed among odorants depending on the brand and brewing process of sake.