High-Electromechanical-Coupling-Coefficient Surface Acoustic Wave Resonator on Ta2O5/Al/LiNbO3Structure

2010 ◽  
Vol 49 (7) ◽  
pp. 07HD21 ◽  
Author(s):  
Hidekazu Nakanishi ◽  
Hiroyuki Nakamura ◽  
Rei Goto
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Coupling Coefficient ◽  
Electromechanical Coupling ◽  
Electromechanical Coupling Coefficient ◽  
Wave Resonator

Surface acoustic wave resonator from thick MOVPE-grown layers of GaN(0001) on sapphire

2002 ◽  
Vol 743 ◽  
Author(s):  
Sverre V. Pettersen ◽  
Thomas Tybell ◽  
Arne Rønnekleiv ◽  
Stig Rooth ◽  
Veit Schwegler ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Electromechanical Coupling ◽  
Film Surface ◽  
Center Frequency ◽  
Electromechanical Coupling Coefficient ◽  
Nitride Film ◽  
Wave Resonator ◽  
Lift Off ◽  
Definition Of

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.

scholarly journals Surface acoustic wave temperature properties in alpha-GeO2 crystal

2021 ◽  
Vol 2131 (5) ◽  
pp. 052098
Author(s):  
R M Taziev
Keyword(s):  
Wave Propagation ◽  
Surface Wave ◽  
Acoustic Wave ◽  
Temperature Coefficient ◽  
Surface Acoustic Wave ◽  
Coupling Coefficient ◽  
Electromechanical Coupling ◽  
Propagation Direction ◽  
Electromechanical Coupling Coefficient ◽  
Wave Propagation Direction

Abstract In this study, the surface acoustic wave (SAW) temperature properties in flux-grown α-GeO2 crystal are numerically investigated. It is shown that the SAW velocity temperature change substantially depends only on the temperature coefficient of three elastic constants: C66, C44 and C14 for crystal cuts and wave propagation directions, where SAW has high electromechanical coupling coefficient. The SAW temperature coefficient of delay (TCD) for these crystal cuts are in the range from -40 ppm /°C to -70 ppm /°C. In contrast to alpha-quartz, the surface wave TCD values are not equal to zero in Z-, Y- , and Z- rotated cuts of α-GeO2 single crystal. Its values are comparable in the magnitude with the surface wave TCD values in lithium tantalate. In the crystal grown from the melt, the interdigital transducer (IDT) conductance has two times larger amplitude than that in hydrothermally grown a-GeO2. The leaky acoustic wave excited by IDT on Z+120°-cut and wave propagation direction along the X-axis, has an electromechanical coupling coefficient 5 times less than that for surface wave.

SURFACE-ACOUSTIC-WAVE FIELD AND ACOUSTO-OPTIC INTERACTION IN AlN/128-DEG-ROTATED Y-CUT X-PROPAGATION LiNbO3

2013 ◽  
Vol 27 (05) ◽  
pp. 1350032
Author(s):  
JUNTAO WANG ◽  
QUN HAN ◽  
JIPING NING ◽  
YANG HE
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Diffraction Efficiency ◽  
Coupling Coefficient ◽  
Electromechanical Coupling ◽  
Guided Wave ◽  
Electromechanical Coupling Coefficient ◽  
Overlap Integral ◽  
Aln Film ◽  
First Time

The efficiency of guided-wave acousto-optic (AO) interaction in AlN /128-deg-rotated Y-cut X-propagation lithium niobate (128-deg YX- LiNbO 3) structure is analyzed theoretically for the first time by determining the overlap integral between the optical and the surface acoustic wave (SAW) field distribution. The results show that the use of an AlN film can increase the phase velocity of SAW, the electromechanical coupling coefficient and the diffraction efficiency of AO interaction. A maximum of 9.33% for the electromechanical coupling coefficient is obtained when the normalized thickness of AlN film equals 0.09. The diffraction efficiency has a significant improvement when the normalized thickness of AlN film is increased from 0 to 0.05. And, the improvement for the TM polarization is more evident than that for the TE polarization. However, for a well-concentrated optical waveguide, the use of an AlN film reduces the diffraction efficiency of the TM polarization when the SAW frequency is low.

Properties of Surface Acoustic Waves in AlN And GaN

2002 ◽  
Vol 743 ◽  
Author(s):  
Jianyu Deng ◽  
Daumantas Ciplys ◽  
Gang Bu ◽  
Michael Shur ◽  
Remis Gaska
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Coupling Coefficient ◽  
Acoustic Waves ◽  
Electromechanical Coupling ◽  
Surface Acoustic Waves ◽  
Elastic Displacement ◽  
Electromechanical Coupling Coefficient ◽  
Coupling Coefficients ◽  
Calculation Results

ABSTRACTThe surface acoustic wave velocities, electromechanical coupling coefficients, and the spatial distributions of both elastic displacement and electric potential have been calculated for various configurations of gallium nitride and aluminum nitride. The electromechanical coupling coefficient values of 0.13 % in GaN and 0.29 % in AlN have been predicted. The maximum electromechanical coupling coefficient values of 0.24 % at Euler angles (0, 54°, 90°) in GaN and 1.08 % at (0, 53°, 90°) in AlN have been found. For GaN layer-on- sapphire substrate structures, the SAW velocity and electromechanical coupling coefficient have been calculated as functions of layer thickness and acoustic wavelength. The experimentally measured values of the surface acoustic wave velocity and electromechanical coupling coefficient are in satisfactory agreement with the calculation results.

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