Publications (23)8.94 Total impact
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Article: GHz frequency ZnO/Si SAW device
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ABSTRACT: The demand for high-frequency low-loss filters generates intensive research on innovative wave guide solutions. In this work, a GHz SAW device based on a ZnO/Si structure was fabricated using classical UV photolithography. The thickness of the piezoelectric thin film was optimized and a specific interdigital transducer structure was used to generate third and fifth harmonic guided waves at 2.5 GHz and 3.5 GHz, respectively, with an aluminum strip larger than 1 micrometer. Different modes have been measured and theoretically identified thanks to an advanced finite-element/boundary-element- based model. Good agreement is found between theory and experiments. The high-frequency modes have been fully characterized, allowing for accurate design of SAW devices exploiting such modes.IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control 03/2008; · 1.69 Impact Factor -
Article: High-frequency surface acoustic waves excited on thin-oriented LiNbO3 single-crystal layers transferred onto silicon
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ABSTRACT: The need for high-frequency, wide-band filters has instigated many developments based on combining thin piezoelectric films and high acoustic velocity materials (sapphire, diamond-like carbon, silicon, etc.) to ease the manufacture of devices operating above 2 GHz. In the present work, a technological process has been developed to achieve thin-oriented, single-crystal lithium niobate (LiNbO<sub>3</sub>) layers deposited on (100) silicon wafers for the fabrication of radio-frequency (RF) surface acoustic wave (SAW) devices. The use of such oriented thin films is expected to favor large coupling coefficients together with a good control of the layer properties, enabling one to chose the best combination of layer orientation to optimize the device. A theoretical analysis of the elastic wave assumed to propagate on such a combination of material is first exposed. Technological aspects then are described briefly. Experimental results are presented and compared to the state of artIEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control 05/2007; · 1.69 Impact Factor -
Conference Proceeding: P1I-5 Micro-Machined, All Quartz Package, Passive Wireless SAW Pressure and Temperature Sensor
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ABSTRACT: An example of SAW P&T sensor is shown. This sensor is to operate for TPMS using the 434 MHz ISM band. Design of this sensor is based on simplicity, leading to micro-machined all quartz SAW device. Details of design process, realization and sensor responses are shownUltrasonics Symposium, 2006. IEEE; 11/2006 -
Article: Photonics Europe
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ABSTRACT: If a number of experiments aiming at demonstrating fundamental properties of phononic crystals have been successfully implemented, a need for enlarging both the research and the application fields of these structures has more recently risen. Surface acoustic waves appear as appealing candidates to set a new ground for illustrative experiments involving some different physical concepts from those usually observed when dealing with bulk waves. The possibility of a direct excitation of these surface waves on a piezoelectric material, and their already extensive use in ultrasonics also make them an interesting basis for phononic crystal based, acoustic signal processing devices. In this work, wave propagation in a square lattice, piezoelectric phononic crystal consisting of air holes etched in a lithium niobate matrix is both theoretically and experimentally investigated. The crystal was fabricated by reactive ion etching of a bulk lithium niobate substrate. Standard interdigital transducers were used to characterize the phononic structure by direct electrical generation and detection of surface waves. A full band gap around 200 MHz was experimentally demonstrated, and close agreement is found with theoretical predictions.© (2006) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.04/2006; -
Conference Proceeding: Fast and precise multi-purpose p-matrix simulation tool ~ built-in features and application examples
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ABSTRACT: Not AvailableUltrasonics Symposium, 2005 IEEE; 10/2005 -
Conference Proceeding: Analysis of saw devices using FEM/BEM method and parallel computing
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ABSTRACT: Not AvailableUltrasonics Symposium, 2005 IEEE; 10/2005 -
Conference Proceeding: New theoretical and experimental results on high frequency surface acoustic waves excited on oriented LiNbO3 single crystal layers transferred
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ABSTRACT: Not AvailableUltrasonics Symposium, 2005 IEEE; 10/2005 -
Article: Prediction of the thermal sensitivity of surface acoustic waves excited under a periodic grating of electrodes
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ABSTRACT: The prediction of the temperature sensitivity of surface acoustic wave (SAW) devices still requires improvement because the nature of the implemented surface modes and the devices' complexity strongly change from the early basic Rayleigh-wave-based devices. To address this problem, a theoretical analysis and a numerical tool have been developed to predict the thermal dispersion of general electro-acoustic devices. The proposed model accounts for the electrode contribution to the frequency-temperature law. The computed thermal sensitivities are compared to experimental results for different kinds of substrates and waves.IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control 09/2005; · 1.69 Impact Factor -
Article: Simulations of surface acoustic wave devices built on stratified media using a mixed finite element/boundary integral formulation
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ABSTRACT: The demand for high frequency surface acoustic wave devices for modern telecommunication applications imposes the development of devices able to answer the manufacturer requirements. The use of high velocity substrates for which a piezoelectric layer is required to excite and detect surface waves has been widely investigated and requires the implementation of accurate theoretical tools to identify the best combinations of material. The present paper proposes a mixed formulation combining finite element analysis with a boundary integral method to accurately simulate the capability of massive periodic interdigital transducers to excite and detect guided acoustic waves in layered media. The proposed model is exploited for different typical configurations. © 2004 American Institute of Physics.Journal of Applied Physics 12/2004; 96(12):7731-7741. · 2.17 Impact Factor -
Conference Proceeding: Evaluation of the P-matrix parameters frequency variation using periodic FEM/BEM analysis [SAW device simulation]
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ABSTRACT: An original approach is proposed to predict and to take into account the frequency variation of the P-matrix parameters in the simulations. The proposed method is applied to well known Rayleigh and dispersive leaky waves for validation. The computed dispersion laws are compared to experimental results for different kinds of substrates and waves.Ultrasonics Symposium, 2004 IEEE; 09/2004 -
Conference Proceeding: Prediction of the thermal sensitivity of surface acoustic waves excited under a periodic grating of electrodes
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ABSTRACT: A theoretical analysis and a numerical tool have been developed to predict the thermal dispersion of general electroacoustic devices. The proposed model accounts for electrode contribution to the frequency vs. temperature law. The computed thermal sensitivities are compared to experimental results for different kinds of substrates and waves.Ultrasonics, 2003 IEEE Symposium on; 11/2003 -
Conference Proceeding: SAW device analysis using a combination of FEM/BEM calculations and scanning interferometer measurements
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ABSTRACT: Scanning laser interferometry has proven useful in the identification of novel acoustic loss phenomena. However, it remains challenging to provide a rigorous physical interpretation of the details of the optically measured acoustic field distribution. With the help of our powerful FEM/BEM finite transducer model, we can make a direct comparison between the measured and simulated acoustic field distributions. This enables us to search and correct for unwanted acoustic phenomena which can deteriorate the filter performance. Here we focus on the modeling of the stress at the interface between the electrodes and the substrate. We describe the FEM/BEM tool for finite transducers that we have developed and its validation with optical Michelson interferometer scans. We show how it is possible to evaluate and optimize the power-handling properties of a SAW device structure.Ultrasonics, 2003 IEEE Symposium on; 11/2003 -
Conference Proceeding: Thin layer mechanical constants extraction using SAW and stratified Green functions - examples of SAW sensitivity to silica layer
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ABSTRACT: A complete sequence of softwares has been developed to identify mechanical parameters of thin layers made of aluminum and silica deposited on piezoelectric substrates. It starts from SAW (surface acoustic wave) devices measurements and the software's sequence includes - automatic extraction of SAW velocities from measurements - computation of SAW velocity in layered media - automatic identification of material parameters to fit extracted SAW velocities. The sequence is completed with a powerful periodic FEA/BIM (finite element analysis/boundary integral method) software which enables to take into account the presence of a silica layer over aluminum IDT (inter-digited transducer). The paper describes the overall method and gives some numerical results for quartz substrate.Ultrasonics, 2003 IEEE Symposium on; 11/2003 -
Article: Interface acoustic waves properties in some common crystal cuts
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ABSTRACT: Interface acoustic waves (IAWs), also termed boundary waves, propagate at the interface between two solids. We present two IAW numerical analysis tools, inspired from well established surface acoustic wave (SAW) methods. First, the interface effective permittivity is derived for arbitrary piezoelectric solids and is used to estimate some basic parameters of IAWs. The harmonic admittance for an interface excitation is then derived from the interface effective permittivity, in much the same way the harmonic admittance for surface excitation is obtained from the (surface) effective permittivity. The finite electrode thickness is neglected in this problem analysis. The harmonic admittance is used to model propagation in the case when an infinite periodic interdigital transducer is located at the interface. Simulation results are commented upon for some usual piezoelectric material cuts and the paper outlines a modal selection specific to IAWs as compared with SAWs. The temperature dependence of the resonance frequency is also estimated.IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control 11/2003; · 1.69 Impact Factor -
Conference Proceeding: Simulation of cMUT radiating in water using a mixed finite element/boundary element approach
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ABSTRACT: A 2D finite element analysis of cMUT is proposed, taking into account periodicity and radiation in fluids. The convergence of the calculation is verified using non periodic computations. The capability of cMUT radiating in water to generate low velocity wave guided at the fluid/silicon interface is theoretically pointed out.Ultrasonics Symposium, 2002. Proceedings. 2002 IEEE; 11/2002 -
Conference Proceeding: Oriented lithium niobate layers transferred on 4 [100] silicon wafer for RF SAW devices
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ABSTRACT: A technological process has been developed to achieve a thin oriented Lithium Niobate layer deposited on [100] Si wafers for the fabrication of SAW devices integrable on silicon. The theoretical analysis of the elastic wave assumed to propagate on such combination of material is first reported. Technological aspects are then briefly described. Finally, experimental results are presented and compared to the state of art.Ultrasonics Symposium, 2002. Proceedings. 2002 IEEE; 11/2002 -
Conference Proceeding: Numerical simulation and comparison of membrane and solidly mounted FBAR's
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ABSTRACT: With the increase in operating frequencies of new wireless communication standards, Surface Acoustic Wave (SAW) devices are now facing competitors, such as thin film bulk acoustic resonators (FBARs). FBAR components are expected to overcome some of the limits of SAW components, and to provide miniature, high-performance and high-frequency filters. In this paper, we compare single resonator responses to more realistic configurations:a piezoelectric layer with relatively thick electrodes and a Solidly Mounted Resonator (SMR) with an acoustic mirror, and a resonator supported by a membrane. We then discuss how to adjust the relative thickness of the piezoelectric layer and of the electrodes to comply with frequency requirements for filtering applications.Ultrasonics Symposium, 2002. Proceedings. 2002 IEEE; 11/2002 -
Conference Proceeding: Stabilization of the simulation of saw devices on stratified structures: application to transverse plate mode resonators
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ABSTRACT: Two approaches are investigated to model accurately the physical characteristics of plate mode devices, and more particularly of resonators. They are respectively based on finite element analysis (FEA) and on mixing FEA with a boundary integral method (FEA/BIM). In the later case, using a transfer matrix approach for the computation of the spectral Green's function results in numerical instabilities for large layer thickness or large slowness. A new stable algorithm is described for the computation of the spectral Green's function of a multilayer structure, that is inherently numerically stable. The main parameters of wave propagation (velocity, coupling factor, reflection coefficient) can then be estimated considering an infinite periodic structure and computing the harmonic admittance. For comparison with measurements of quartz transverse plate mode resonators, the estimated parameters can be inserted in a P-matrix model. Theory and experiments are found to comply well for both the pure FEA and the FEA/BIM approachesFrequency Control Symposium and PDA Exhibition, 2001. Proceedings of the 2001 IEEE International; 02/2001 -
Conference Proceeding: Surface acoustic waves propagating on piezoelectric substrates under periodic arrays with large electrode thickness
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ABSTRACT: It has been shown theoretically and demonstrated experimentally that shear horizontal (SH) surface waves can exist when the surface of an isotropic substrate is perturbed by a strong corrugation, for instance consisting of deep grooves etched in the substrate, whereas these waves cannot exist without this perturbation. It is shown in this paper that a periodic array of metallic electrodes (wires) exhibiting large aspect ratios deposited over a piezoelectric substrate gives rise to surface acoustic waves with general polarization. The admittance of an interdigital transducer (IDT), which is a basic tool for predicting the wave parameters, is calculated by a combination of finite element analysis and a boundary integral method. This approach has been extended to obtain the polarization of the acoustic waves. For different piezoelectric substrates, we predict various surface acoustic modes and their polarization. Along with mostly-SH modes we also find modes mostly polarized in the sagittal plane. We discuss the frequency behavior of the surface modes as a function of the electrode height compared to the periodFrequency Control Symposium and PDA Exhibition, 2001. Proceedings of the 2001 IEEE International; 02/2001 -
Conference Proceeding: A plane-wave-expansion approach for modelling acoustic propagation in 2D and 3D piezoelectric periodic structures
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ABSTRACT: Piezocomposite transducers have been developed for medical ultrasound imaging and non destructive evaluation to overcome the limitations of standard 1D probes. In the present work we propose to use an extended plane-wave-expansion (PWE) method in conjunction with the Fahmy-Adler formulation of the Christoffel problem, usually used in SAW calculations, to simulate actual 1D-and 2D-periodic piezoelectric composite devices. We are able to establish the spatial and frequency distribution of both bulk and surface acoustic waves and, in the case of an electrical excitation, to compute the mode distribution along the thickness of the plate and the harmonic admittanceUltrasonics Symposium, 2001 IEEE; 02/2001
Top co-authors
Top Journals
Institutions
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2003–2007
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Université de Nice - Sophia Antipolis
Valbonne, Provence-Alpes-Cote d'Azur, France
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1999–2003
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Université de Franche-Comté
- Institut FEMTO-ST
Besançon, Franche-Comte, France
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