scholarly journals Mode Analysis of Pt/LGS Surface Acoustic Wave Devices

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7111
Author(s):  
Hongsheng Xu ◽  
Hao Jin ◽  
Shurong Dong ◽  
Xinyu Song ◽  
Jinkai Chen ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Three Dimensional ◽  
Euler Angle ◽  
Mode Analysis ◽  
Single Chip ◽  
Leaky Waves ◽  
Pt Electrode ◽  
Sensing Applications ◽  
Saw Devices

Platinum (Pt) gratings on langasite (LGS) substrates are a widely used structures in high temperature surface acoustic wave (SAW) devices. Multiple modes can be excited in Pt/LGS SAW devices owing to the heavy weight of the Pt electrode and leaky waves in the LGS substrate. In this work, we report on a detailed mode analysis of Pt/LGS SAW devices, where three commonly used LGS cuts are considered. A three-dimensional (3D) finite element method (FEM) numerical model was developed, and the simulation and experiment results were compared. The experiment and simulation results showed that there are two modes excited in the Pt/LGS SAW devices with Euler angle (0°, 138.5°, 27°) and (0°, 138.5°, 117°), which are Rayleigh-type SAW and SH-type leaky wave, respectively. Only the Rayleigh-type mode was observed in the Pt/LGS SAW devices with Euler angle (0°, 138.5°, 72°). It was found that the acoustic velocities are dependent on the wavelength, which is attributed to the change of wave penetration depth in interdigital transducers (IDTs) and the velocity dispersion can be modulated by the thickness of the Pt electrode. We also demonstrated that addition of an Al2O3 passivation layer has no effect on the wave modes, but can increase the resonant frequencies. This paper provides a better understanding of the acoustic modes of Pt/LGS SAW devices, as well as useful guidance for device design. It is believed that the Rayleigh-type SAW and SH-type leaky waves are potentially useful for dual-mode sensing applications in harsh environments, to achieve multi-parameter monitoring or temperature-compensation on a single chip.

Surface Acoustic Wave Sensors Deposited on AlN Thin Films

2009 ◽  
Vol 1202 ◽  
Author(s):  
J. L. Justice ◽  
O. M. Mukdadi ◽  
D. Korakakis
Keyword(s):  
Thin Films ◽  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Piezoelectric Materials ◽  
Theoretical Calculations ◽  
Si Substrates ◽  
Sensing Applications ◽  
Saw Devices ◽  
Inherent Frequency ◽  
Wave Sensors

AbstractOver the past few decades, there has been considerable research and advancement in surface acoustic wave (SAW) technology. At present, SAW devices have been highly successful as frequency band pass filters for the mobile telecommunications and electronics industries. In addition to their inherent frequency selectivity, SAW devices are also highly sensitive to surface perturbations. This sensitivity, along with a relative ease of manufacture, makes SAW devices ideally suited for many sensing applications including mass, pressure, temperature, and biosensors. In the area of biosensing, surface plasmon resonance (SPR) and quartz crystal microbalances (QCM) are still in the forefront of research and development, but advancement in SAW sensors could prove to have significant advantages over these technologies. This study investigates the advantages of using aluminum nitride (AlN) as a material for SAW sensors. AlN retains its piezoelectric properties at relatively high temperatures when compared to more common piezoelectric materials such as lead zirconium titanate (PZT), lithium tantalate (LiTaO3) and zinc oxide (ZnO). AlN is also a very robust material making it suitable for biosensing applications where the sensing target is selectively absorbed by an active layer on the device which may attack the piezoelectric layer. AlN thin films of different thicknesses have been deposited on Si substrates by DC reactive sputtering. Rayleigh-wave SAW devices have been fabricated by the deposition of platinum contacts and interdigital transducers (IDTs) onto AlN thin films using standard photolithographic processes. Experiments have been conducted to measure Rayleigh velocities, resonant frequencies, and insertion loss. Experimental results are compared to theoretical calculations.

scholarly journals On the Performance Evaluation of Commercial SAW Resonators by Means of a Direct and Reliable Equivalent-Circuit Extraction

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 303
Author(s):  
Giovanni Gugliandolo ◽  
Zlatica Marinković ◽  
Giuseppe Campobello ◽  
Giovanni Crupi ◽  
Nicola Donato
Keyword(s):  
Performance Evaluation ◽  
Acoustic Wave ◽  
Equivalent Circuit ◽  
Surface Acoustic Wave ◽  
Equivalent Circuit Model ◽  
Practical Applications ◽  
Saw Devices ◽  
S Parameter ◽  
Commercial Device ◽  
Saw Resonators

Nowadays, surface acoustic wave (SAW) resonators are attracting growing attention, owing to their widespread applications in various engineering fields, such as electronic, telecommunication, automotive, chemical, and biomedical engineering. A thorough assessment of SAW performance is a key task for bridging the gap between commercial SAW devices and practical applications. To contribute to the accomplishment of this crucial task, the present paper reports the findings of a new comparative study that is based on the performance evaluation of different commercial SAW resonators by using scattering (S-) parameter measurements coupled with a Lorentzian fitting and an accurate modelling technique for the straightforward extraction of a lumped-element equivalent-circuit representation. The developed investigation thus provides ease and reliability when choosing the appropriate commercial device, depending on the requirements and constraints of the given sensing application. This paper deals with the performance evaluation of commercial surface acoustic wave (SAW) resonators by means of scattering (S-) parameter measurements and an equivalent-circuit model extracted using a reliable modeling procedure. The studied devices are four TO-39 packaged two-port resonators with different nominal operating frequencies: 418.05, 423.22, 433.92, and 915 MHz. The S-parameter characterization was performed locally around the resonant frequencies of the tested SAW resonators by using an 8753ES Agilent vector network analyzer (VNA) and a home-made calibration kit. The reported measurement-based study has allowed for the development of a comprehensive and detailed comparative analysis of the performance of the investigated SAW devices. The characterization and modelling procedures are fully automated with a user-friendly graphical user interface (GUI) developed in the Python environment, thereby making the experimental analysis faster and more efficient.

Low loss surface acoustic wave SAW devices based on Al1-xMxN (M=Cr, Y, Sc) thin films

2021 ◽  
pp. 412990
Author(s):  
Saad Amara ◽  
Fares Kanouni ◽  
Farouk Laidoudi ◽  
Khaled Bouamama
Keyword(s):  
Thin Films ◽  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Low Loss ◽  
Saw Devices

Surface acoustic wave devices fabricated on epitaxial AlN film

2016 ◽  
Vol 09 (02) ◽  
pp. 1650034 ◽  
Author(s):  
Junning Gao ◽  
Zhibiao Hao ◽  
Lang Niu ◽  
Lai Wang ◽  
Changzheng Sun ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Epitaxial Film ◽  
Stop Band ◽  
Crystalline Quality ◽  
Center Frequency ◽  
Pass Band ◽  
Saw Devices ◽  
Aln Film

This paper reports surface acoustic wave (SAW) devices fabricated on AlN epitaxial film grown on sapphire, aiming to avoid the detrimental polarization axis inconsistency and refrained crystalline quality of the normally used polycrystalline AlN films. Devices with center frequency of 357 MHz and 714 MHz have been fabricated. The stop band rejection ratio of the as-obtained device reaches 24.5 dB and the pass band ripple is profoundly smaller compared to most of the reported AlN SAW devices with the similar configuration. Judging from the rather high edge dislocation level of the film used in this study, the properties of the SAW devices have great potential to be improved by further improving the crystalline quality of the film. It is then concluded that the AlN epitaxial film is favorable for high quality SAW devices to meet the high frequency and low power consumption challenges facing the signal processing components.

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