Determination of the Electromechanical Coupling Coefficient of Thin‐Film Cadmium Sulphide

1968 ◽  
Vol 39 (6) ◽  
pp. 2863-2868 ◽  
Author(s):  
A. J. Bahr ◽  
Ian N. Court
Keyword(s):  
Thin Film ◽  
Coupling Coefficient ◽  
Electromechanical Coupling ◽  
Cadmium Sulphide ◽  
Electromechanical Coupling Coefficient

Characteristics Analysis of Saw Filter Using Al0.36Ga0.64N Thin Film

2002 ◽  
Vol 720 ◽  
Author(s):  
Sun-Ki Kim ◽  
Min-Jung Park ◽  
Cheol-Yeong Jang ◽  
Hyun-Chul Choi ◽  
Jung-Hee Lee ◽  
...  
Keyword(s):  
Thin Film ◽  
Insertion Loss ◽  
Coupling Coefficient ◽  
Electromechanical Coupling ◽  
Side Lobe ◽  
Electromechanical Coupling Coefficient ◽  
Device Performance ◽  
Saw Devices ◽  
Characteristics Analysis ◽  
Temperature Coefficient Of Frequency

AbstractAlxGa1-xN sample with x=0.36 was epitaxially grown on sapphire by MOCVD. SAW velocity of 5420 m/s and TCF (temperature coefficient of frequency) of -51.20 ppm/°C were measured from the SAW devices fabricated on the AlxGa1-xN sample, when kh value was 0.078, at temperatures between –30 °C and 60 °C Electromechanical coupling coefficient was ranged from 1.26 % to 2.22 %. The fabricated SAW filter have shown a good device performance with insertion loss of -33.853 dB and side lobe attenuation of 20 dB.

ON THE DETERMINATION OF ELECTROMECHANICAL COUPLING COEFFICIENTS IN A POLYRESONANT PIEZOELECTRIC VIBRATOR

1955 ◽  
Vol 33 (9) ◽  
pp. 504-508 ◽  
Author(s):  
E. A. G. Shaw
Keyword(s):  
Coupling Coefficient ◽  
Electromechanical Coupling ◽  
Electromechanical Coupling Coefficient ◽  
Frequency Interval ◽  
Coupling Coefficients ◽  
Small Frequency ◽  
Piezoelectric Vibrator ◽  
The Many ◽  
True Values

The well-known relationship between the electromechanical coupling coefficient and the separation (σ) of resonance and antiresonance frequencies requires modification where several significant modes occur within a small frequency interval. An expression is given for the "true" values of σ (i.e. those which would arise if each mode existed alone) in terms of the many moded system. The analysis neglects mechanical and electrical losses.

scholarly journals Fabrication of a 3.5-GHz Solidly Mounted Resonator by Using an AlScN Piezoelectric Thin Film

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1151
Author(s):  
Chan-Yu Chung ◽  
Ying-Chung Chen ◽  
Yu-Cheng Chen ◽  
Kuo-Sheng Kao ◽  
Yu-Chen Chang
Keyword(s):  
Thin Film ◽  
Resonance Frequency ◽  
Coupling Coefficient ◽  
Electromechanical Coupling ◽  
Bragg Reflector ◽  
Electromechanical Coupling Coefficient ◽  
Axis Orientation ◽  
X Ray ◽  
Aln Film ◽  
Piezoelectric Thin Film

In this study, a 3.5-GHz solidly mounted resonator (SMR) was developed by doping scandium in aluminum nitride to form AlScN as the piezoelectric thin film. Molybdenum (Mo) of 449 nm thickness and silicon dioxide (SiO2) of 371 nm thickness were used as the high and low acoustic impedance films, respectively, which were alternately stacked on a silicon substrate to form a Bragg reflector. Then, an alloy target with atomic ratio of 15% Sc was adopted to deposit the piezoelectric AlScN thin film on the Bragg reflector, using a radio frequency magnetron sputtering system. The characteristics of the c-axis orientation of the AlScN thin films were optimized by adjusting sputtering parameters as sputtering power of 250 W, sputtering pressure of 20 mTorr, nitrogen gas ratio of 20%, and substrate temperature of 300 °C. Finally, a metal top electrode was coated to form a resonator. The X-ray diffraction (XRD) analysis showed that the diffraction peak angles of the AlScN film shifted towards lower angles in each crystal phase, compared to those of AlN film. The energy dispersive X-ray spectrometer (EDX) analysis showed that the percentage of scandium atom in the film is about 4.5%, regardless of the sputtering conditions. The fabricated resonator exhibited a resonance frequency of 3.46 GHz, which was a small deviation from the preset resonance frequency of 3.5 GHz. The insertion loss of −10.92 dB and the electromechanical coupling coefficient of 2.24% were obtained. As compared to the AlN-based device, the AlScN-based resonator exhibited an improved electromechanical coupling coefficient by about two times.

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