scholarly journals Large electromechanical coupling factor film bulk acoustic resonator with X-cut LiNbO3 layer transfer

2009 ◽  
Vol 95 (18) ◽  
pp. 182106 ◽  
Author(s):  
M. Pijolat ◽  
S. Loubriat ◽  
S. Queste ◽  
D. Mercier ◽  
A. Reinhardt ◽  
...  
2015 ◽  
Vol 2015 ◽  
pp. 1-8
Author(s):  
Tao Zhang ◽  
Fujun Liang ◽  
Min Li ◽  
Shaorong Li ◽  
Huafeng Pang ◽  
...  

The resonance frequency,fs, and the effective electromechanical coupling factor,keff2, of thin film bulk acoustic resonators (FBARs) are derived by transfer matrix method. The effects of thickness and density of electrode onfsandkeff2with different piezoelectric layers are investigated by numerical calculation method. The results show that thickness and density of electrode affectfsobviously, especially in large thickness and density area. Moreover, the effects of thickness, density, and acoustic velocity of electrode onkeff2of FBAR were also studied. The results show that there is a maximumkeff2corresponding to the composition of thickness and density of electrode which is about 20% over the original electromechanical factor of piezoelectric film.keff2is in the direct proportion to the densityρeandveof electrode, respectively. The electrode thickness affectskeff2small with highve; moreover, whenveis high enough, thenkeff2has almost nothing to do withde.keff2always rises with electrode thickness first and then descends with its rising, and the thickness corresponding to the maximumkeff2is different with different electrode, but it always locates in the special area. All above results indicate that the thickness, density, and acoustic velocity of electrode are so important that these results can be applied to design FBAR.


2012 ◽  
Vol 569 ◽  
pp. 149-152
Author(s):  
Tao Zhang ◽  
Min Li ◽  
Ping Liu ◽  
Bin Sun ◽  
Sheng Nan Zhou

In this paper, the transmitting line method is applied to analyze the properties of FBAR, and the input impedance equation is obtained, and the series resonance frequency fs and the parallel resonance frequency fp are calculated by this method. Moreover, the elastic effects of the electrode on the effective electromechanical coupling factor, k2eff , and the resonance factor, Qs> , of FBAR are investigated by the transmitting line method. Results indicate that the acoustic impedance ratio of the electrode to the piezo-film dominantly determines the behaviors of the k2eff , the variation of Qs versus the thickness of the electrode crucially depends on the acoustic impedance ratio of electrode to piezoelectric films. The results will be applied in the theoretical optimization of FBAR, which are available to optimize the fabrications of FBARs and similar devices.


2018 ◽  
Vol 140 (3) ◽  
Author(s):  
Rafik Serhane ◽  
Fayçal Hadj-Larbi ◽  
Abdelkader Hassein-Bey ◽  
Abdelkrim Khelif

In this work, we investigate numerically the propagation of Lamb waves in a film bulk acoustic resonator (FBAR) structure formed by piezoelectric ZnO layer sandwiched between two Mo electrodes coupled with Bragg reflectors; the system is thus considered as a phononic-crystal (PnC) plate. The aim is to suppress the first-order symmetric Lamb wave mode considered as a spurious mode caused by the establishment of a lateral standing wave due to the reflection at the embedded lateral extremities of the structure; this spurious mode is superposing to the main longitudinal mode resonance of the FBAR. The finite element study, using harmonic and eigen-frequency analyses, is performed on the section of FBAR structure coupled with the PnC. In the presence of PnC, the simulation results show the evidence of a selective band gap where the parasitic mode is prohibited. The quality factor of the FBAR is enhanced by the introduction of the PnC. Indeed, the resonance and antiresonance frequencies passed from 1000 and 980 (without PnC) to 2350 and 1230 (with PnC), respectively. This is accompanied by a decrease in the electromechanical coupling coefficient from 10.60% to 6.61%.


2000 ◽  
Vol 655 ◽  
Author(s):  
Paul Kirby ◽  
Qing-Xin Su ◽  
Eiju Komuro ◽  
Masaaki Imura ◽  
Qi Zhang ◽  
...  

AbstractBoth ZnO and PZT Thin Film Bulk Acoustic Resonator filters were fabricated, tested and modeled in this study. The development of an accurate Mason model allows the effect of particular parasitic components on the microwave s-parameters in the region of the series and parallel resonances to be identified. The parasitic components that limit the performance of our ZnO and PbZr0.3Ti0.7O3 Thin Film Bulk Acoustic Resonator filters are analysed. From an analysis of PbZr0.3Ti0.7O3 Thin Film Bulk Acoustic Resonator measurements values for the longitudinal acoustic velocity and electromechanical coupling coefficient can be derived. Measured PbZr0.3Ti0.7O3 Thin Film Bulk Acoustic Resonator filter responses confirm that the larger electromechanical coupling coefficients in this material compared to ZnO give wider filter band-widths.


2011 ◽  
Vol 3 (2) ◽  
pp. 91-98 ◽  
Author(s):  
Xu Zhang ◽  
Wencheng Xu ◽  
Junseok Chae

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6438
Author(s):  
Guangtao Lu ◽  
Xin Zhu ◽  
Tao Wang ◽  
Zhiqiang Hao ◽  
Bohai Tan

A novel piezoceramic stack-based smart aggregate (PiSSA) with piezoceramic wafers in series or parallel connection is developed to increase the efficiency and output performance over the conventional smart aggregate with only one piezoelectric patch. Due to the improvement, PiSSA is suitable for situations where the stress waves easily attenuate. In PiSSA, the piezoelectric wafers are electrically connected in series or parallel, and three types of piezoelectric wafers with different electrode patterns are designed for easy connection. Based on the theory of piezo-elasticity, a simplified one-dimensional model is derived to study the electromechanical, transmitting and sensing performance of PiSSAs with the wafers in series and parallel connection, and the model was verified by experiments. The theoretical results reveal that the first resonance frequency of PiSSAs in series and parallel decreases as the number or thickness of the PZT wafers increases, and the first electromechanical coupling factor increases firstly and then decrease gradually as the number or thickness increases. The results also show that both the first resonance frequency and the first electromechanical coupling factor of PiSSA in series and parallel change no more than 0.87% as the Young’s modulus of the epoxy increases from 0.5 to 1.5 times 3.2 GPa, which is helpful for the fabrication of PiSSAs. In addition, the displacement output of PiSSAs in parallel is about 2.18–22.49 times that in series at 1–50 kHz, while the voltage output of PiSSAs in parallel is much less than that in parallel, which indicates that PiSSA in parallel is much more suitable for working as an actuator to excite stress waves and PiSSA in series is suitable for working as a sensor to detect the waves. All the results demonstrate that the connecting type, number and thickness of the PZT wafers should be carefully selected to increase the efficiency and output of PiSSA actuators and sensors. This study contributes to providing a method to investigate the characteristics and optimize the structural parameters of the proposed PiSSAs.


2001 ◽  
Vol 687 ◽  
Author(s):  
Jürgen Brünahl ◽  
Alex M. Grishin ◽  
Sergey I. Khartsev ◽  
Carl Österberg

AbstractWe report on comprehensive characterization of piezoelectric shear mode inkjet actuators micromachined into bulk Pb(Zr0.53Ti0.47)O3 (PZT) ceramics. The paper starts with an overview of different inkjet technologies such as continuous jet and drop-on-demand systems, whereat main attention is turned on piezoelectric systems particularly Xaar-type shear mode inkjet color printheads. They are an example of complex microelectromechanical systems (MEMS) and comprise a ferroelectric array of 128 active ink channels (75νm wide and 360νm deep). Detailed information about manufacturing and principles of operation are given. Several techniques to control manufacturing processes and to characterize properties of the piezoelectric material are described: dielectric spectroscopy to measure dielectric permittivity ε and loss tanσ; ferroelectric hysteresis P-E loop tracing to get remnant polarization Pr and coercive field Ec, and a novel pulsed technique to quantify functional properties of the PZT actuator such as acoustic resonant frequencies and electromechanical coupling factor. Stroboscope technique has been employed to find correlation between the degradation of ink-jet performance and heat/high voltage treatment resulting in ferroelectric fatigue.


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