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

2022 ◽  
Author(s):  
Yudai Fujii ◽  
Takumi Fujimaki ◽  
Masashi Suzuki ◽  
Shoji Kakio
Keyword(s):  
Thin Plate ◽  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Coupling Factor ◽  
Euler Angles ◽  
The Finite Element Method ◽  
Similar Material ◽  
Resonance Properties ◽  
Temperature Coefficient Of Frequency ◽  
Lower Temperature

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%.

LEAKY SURFACE ACOUSTIC WAVES IN SINGLE-CRYSTAL AlN SUBSTRATE

2004 ◽  
Vol 14 (03) ◽  
pp. 837-846 ◽  
Author(s):  
GANG BU ◽  
DAUMANTAS CIPLYS ◽  
MICHAEL S. SHUR ◽  
LEO J. SCHOWALTER ◽  
SANDRA B. SCHUJMAN ◽  
...  
Keyword(s):  
Single Crystal ◽  
Acoustic Waves ◽  
Electromechanical Coupling ◽  
Surface Acoustic Waves ◽  
Propagation Direction ◽  
Electromechanical Coupling Coefficient ◽  
Coupling Coefficients ◽  
Leaky Waves ◽  
Temperature Coefficient Of Frequency ◽  
Piezoelectric Constants

We report on the velocity V and the electromechanical coupling coefficient K2 of the first and the second leaky surface acoustic waves in various propagation directions in the a-plane AlN single-crystal. For c-propagation direction, the second leaky wave exhibited the velocity of 11016 m/s and K2 of 0.45%. For this direction, the temperature coefficient of frequency was found to be -30 ppm/°C. A near match of the velocities of the plane and leaky waves in the a-plane AlN allowed us to establish analytical relationships between the piezoelectric and elastic constants. A full set of elastic and piezoelectric constants of AlN has been evaluated by fitting the measured and calculated dependencies of velocities and electromechanical coupling coefficients on the propagation direction for both Rayleigh and leaky waves.

Analysis of propagation characteristics of Rayleigh surface acoustic waves on Yb0.33Al0.67N piezoelectric films/high-velocity substrates

2022 ◽  
Author(s):  
Masashi Suzuki ◽  
Shoji Kakio
Keyword(s):  
High Velocity ◽  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Film Surface ◽  
Layered Structures ◽  
Coupling Factor ◽  
Propagation Characteristics ◽  
Effective Coupling ◽  
Diamond Substrate ◽  
Coupling Factors

Abstract Piezoelectricity of YbAlN films has recently been shown to be almost as high as that of ScAlN films. YbAlN film surface acoustic wave (SAW) resonators are expected to have a high coupling factor. We theoretically investigated the propagation characteristics of first-mode Rayleigh SAWs (RSAWs) on Yb0.33Al0.67N film/high-velocity Si, sapphire, AlN, SiC, BN, and diamond substrates. The first-mode RSAWs on the YbAlN layered structures had high coupling factors, higher than those on ScAlN layered structures. An enhancement of the effective coupling factor of the first mode RSAWs was observed in polarity inverted YbAlN film/BN or diamond substrate structures.

Ladder Type of Leaky Surface Acoustic Waves Filters on Substrate of Lithium Niobate

2021 ◽  
Vol 23 (3) ◽  
pp. 139-147
Author(s):  
A.S. Koigerov ◽  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Acoustic Waves ◽  
Communication Systems ◽  
Surface Acoustic Waves ◽  
Bandpass Filters ◽  
The Finite Element Method ◽  
Frequency Responses ◽  
Method Of Extraction ◽  
Element Method

High requirements on the electrical parameters of the filters are made in wireless radio communication systems. A number of tasks require bandpass filters with relative bandwidths of 8-12 %. In this case, the filter must have insertion losses of not more than 10 dB, have a rejection is not worse than 40 dB, unevenness in the bandwidth of not more than 1 dB. In addition, the amplitude frequency responses of the filter must have steep slopes due to the closely spaced frequency bands of neighboring communication systems. Due to its small size and other advantages, ladder resonator filters on surface acoustic waves are widely used in communication systems. To realize the high requirements of this type of filters, it is necessary not only to select all the topology parameters of the individual resonators included in the filter very accurately, but also to have a good computational theory and the necessary material parameters for the selected model at the design stage. Purpose: to show on the example of comparison of calculated and experimental frequency responses of ladder filters the validity of the method of extraction of the necessary parameters obtained for an infinite periodic structure by the finite element method for calculating of finite structures of real inter digital transducer and reflective gratings. Results: the method of extraction of parameters necessary for calculation by the method of connected modes on the basis of P-matrices is offered. The technique is based on the analysis of infinite periodic electrodes by the finite element method. Bandpass filters with a relative bandwidth 8-12 % on a piezosubstrate 49° YX LiNbO3 were designed and manufactured based on the proposed theory. It is shown that for this material, the calculation must take into account the direct radiation of bulk acoustic waves, since the design of ladder type filters, the radiation falls into the projected bandwidth of the filters. These calculations are confirmed by the results of experiments.

scholarly journals Numerical study of acoustophoretic manipulation of particles in microfluidic channels

2021 ◽  
pp. 095441192110247
Author(s):  
Jun Ma ◽  
Dongfang Liang ◽  
Xin Yang ◽  
Hanlin Wang ◽  
Fangda Wu ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Acoustic Radiation ◽  
Numerical Study ◽  
Surface Acoustic Waves ◽  
Radiation Force ◽  
Suspended Particles ◽  
Bottom Surface ◽  
Microfluidic Channels ◽  
The Finite Element Method ◽  
First Order

The microfluidic technology based on surface acoustic waves (SAW) has been developing rapidly, as it can precisely manipulate fluid flow and particle motion at microscales. We hereby present a numerical study of the transient motion of suspended particles in a microchannel. In conventional studies, only the microchannel’s bottom surface generates SAW and only the final positions of the particles are analyzed. In our study, the microchannel is sandwiched by two identical SAW transducers at both the bottom and top surfaces while the channel’s sidewalls are made of poly-dimethylsiloxane (PDMS). Based on the perturbation theory, the suspended particles are subject to two types of forces, namely the Acoustic Radiation Force (ARF) and the Stokes Drag Force (SDF), which correspond to the first-order acoustic field and the second-order streaming field, respectively. We use the Finite Element Method (FEM) to compute the fluid responses and particle trajectories. Our numerical model is shown to be accurate by verifying against previous experimental and numerical results. We have determined the threshold particle size that divides the SDF-dominated regime and the ARF-dominated regime. By examining the time scale of the particle movement, we provide guidelines on the device design and operation.

The Notch Filter on Surface Acoustic Wave on Base of Single Phase Unidirectional Transducers

2020 ◽  
Vol 22 (9) ◽  
pp. 493-500
Author(s):  
A.S. Koigerov ◽  
◽  
S.S. Andreychev ◽  
Keyword(s):  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Notch Filter ◽  
Bandpass Filters ◽  
Engineering Systems ◽  
The Finite Element Method ◽  
Notch Filters ◽  
Relative Value ◽  
Selection Of

High requirements on the electrical parameters of the filters are made in radio engineering systems. For bandpass filters, these requirements apply to the squareness coefficient of the amplitude frequency response and rejection. Therefore, the notch filter can be used as a complement to bandpass filters, since it serves to suppress signals in a certain frequency range. Notch filters on surface acoustic waves are not widely used, but they have a number of interesting features and advantages over types of filters that work on other principles. The purpose of the development is to produce a notch filter on surface acoustic waves at 40.05 MHz with 40 dB suppression, a bandstop at the level of -3 dB at least 135 kHz (relative value - 0.34 %), a bandstop at the level of -40 dB at least 35 kHz (relative value - 0.0875 %). Results: a brief classification of notch filters is given. Various variants of passive notch filters are considered. Based on the method of coupling of modes and the finite element method, key elements on surface acoustic waves were calculated and manufactured for a notch filter with the required parameters on a substrate of a 36°YX Quartz piezoelectric material. The key element is a unidirectional transducer of DART type. The scheme is based on a bridge scheme with additional passive tuning elements. It is shown that in order to implement this filter, it is necessary not only to select all the topology parameters of individual key elements included in the filter very precisely, but also to perform precise configuration and selection of passive LC-elements. These calculations are confirmed by the results of experiments.

ANALYSIS OF SAW EXCITATION AND PROPAGATION UNDER PERIODIC METALLIC GRATING STRUCTURES

2000 ◽  
Vol 10 (03) ◽  
pp. 685-734 ◽  
Author(s):  
KEN-YA HASHIMOTO ◽  
TATSUYA OMORI ◽  
MASATSUNE YAMAGUCHI
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Field Analysis ◽  
The Finite Element Method ◽  
Numerical Techniques ◽  
Metallic Grating ◽  
Propagation Properties ◽  
Element Method

This paper reviews numerical techniques used for the analysis of excitation and propagation properties of surface acoustic waves (SAWs) under periodic metallic grating structures. First, the finite element method (FEM), the boundary element method (BEM) and the spectral domain analysis (SDA) are compared for the SAW field analysis. Then it is shown how skillfully excitation and propagation properties are characterized by using the FEM/SDA technique. Extended FEM/SDA theories are also detailed for the analysis of multi-finger grating structures.

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