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 ◽  
...  

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.

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 303
Author(s):  
Giovanni Gugliandolo ◽  
Zlatica Marinković ◽  
Giuseppe Campobello ◽  
Giovanni Crupi ◽  
Nicola Donato

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.


2021 ◽  
pp. 412990
Author(s):  
Saad Amara ◽  
Fares Kanouni ◽  
Farouk Laidoudi ◽  
Khaled Bouamama

2013 ◽  
Vol 273 ◽  
pp. 371-374
Author(s):  
Bao Ping Li ◽  
Yan Liang Zhang

Due to the frequency response periodicity of distributed transmission line, microstrip band-pass filter usually produces parasitic pass-band and outputs harmonics away from the center frequency of main pass-band. Based on the study of rectangular ring defected ground structure, a 5-order microstrip LPF(low-pass filter) was designed using the single-pole band-stop and slow-wave characteristics of the rectangular ring DGS(Defected Ground Structure) and SISS(Step-Impedance Shunt Stub) structure. Compared with traditional LPF, this LPF presents the advantages of compact size, low insertion loss, broad stop-band and high steep. It also validates the requirements of miniaturization and high performance for filters.


2002 ◽  
Vol 743 ◽  
Author(s):  
Sverre V. Pettersen ◽  
Thomas Tybell ◽  
Arne Rønnekleiv ◽  
Stig Rooth ◽  
Veit Schwegler ◽  
...  

ABSTRACTWe report on fabrication and measurement of a surface acoustic wave resonator prepared on ∼10m thick GaN(0001) films. The films were grown by metal-organic vapor phase epitaxy on a c-plane sapphire substrate. The surface morphology of the films were examined with scanning electron and atomic force microscopy. A metallic bilayer of Al/Ti was subsequently evaporated on the nitride film surface. Definition of the resonator interdigital transducers, designed for a wavelength of λ=7.76m, was accomplished with standard UV lithography and lift-off. S-parameter measurements showed a resonator center frequency f0=495MHz at room temperature, corresponding to a surface acoustic wave velocity of 3844m/s. The insertion loss at center frequency was measured at 8.2dB, and the loaded Q-factor was estimated at 2200. Finally, measurements of the resonator center frequency for temperatures in the range 25–155°C showed a temperature coefficient of -18ppm/°C. The intrinsic GaN SAW velocity and electromechanical coupling coefficient were estimated at νSAW=383 1m/s and K2=1.8±0.4·10−3.


Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7111
Author(s):  
Hongsheng Xu ◽  
Hao Jin ◽  
Shurong Dong ◽  
Xinyu Song ◽  
Jinkai Chen ◽  
...  

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.


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