Abstract: A remotely interrogatable passive sensor is provided. The sensor comprises an antenna and at least one surface wave resonator including a transducer with inter-digitated electrodes with two ports on the surface of a piezoelectric substrate, in which the antenna comprises conducting elements connected to the two ports and integrated onto said piezoelectric substrate. Advantageously, the antenna elements are folded on the substrate to enhance compactness. The passive sensor can be used for medical applications such as tissue analysis or arterial pressure measurement.

Abstract: A transponder including a first resonator and a series of one or more second resonators with coupling of evanescent waves exhibiting at least one first resonant mode and one second resonant mode, said first resonator being connected via a first port, to a first means allowing an interrogation, wherein said second resonators are connected via at least one second port, to at least one variable load element capable of modifying coupling conditions of the resonant modes and consequently a response measured on said first port.

Abstract: The invention relates to a surface acoustic wave resonator produced on a cut substrate with propagation axes for which a nonzero directivity exists and comprising at least one central transducer (Tc) exhibiting a central axis, a first array of reflectors (R1) and a second array of reflectors (R2), said arrays being situated on either side of said transducer, characterized in that the two arrays of reflectors exhibit nonsymmetric configurations with respect to the central axis of said central transducer. The introduction of an asymmetry makes it possible to strongly attenuate the parasitic resonances which may appear when the resonators are produced notably on piezoelectric substrates of quartz type or any other material and cut with propagation axes for which there exists a natural directivity (LiTaO3, LiNbO3, langasite, GaPO4, LiB4O7, KNbO3, etc.).

Abstract: The invention relates to a resonator of the harmonic bulk acoustic resonator IIBAR type, comprising a piezoelectric transducer (6) clamped between two electrodes (4, 8) with a strong electroacoustic coupling, cut according to a first cutting angle ?1, and an acoustic substrate (10) with a working frequency acoustic quality coefficient at least equal to 5.1012, cut according to a second cutting angle ?2 with at least one shearing vibration mode. The transducer and the substrate are arranged in such a way that the polarisation direction of the shearing mode of the transducer and the polarisation direction of the shearing of the substrate are aligned, and the second cutting angle ?2 is such that the temperature coefficient of the frequency of the first order CTFB1 corresponding to the shearing mode and to the second cutting angle ?2 is zero with inversion of the sign thereof on either side of, or equal to, a bias.

Abstract: The elementary filter of the HBAR type includes two resonators (20, 22) of the HBAR type which are each formed by a transducer (8) and a substrate (12) which are coupled in a suitable manner by electroacoustic waves. The first resonator (20), the second resonator (22) and the coupling element (28) by way of evanescent waves include the same monobloc acoustic substrate (12) which is arranged facing and coupled to the piezoelectric transducer (8) by waves having the same longitudinal or transverse vibration mode through the same reference electrode (10).

Abstract: A method of remotely interrogating a passive sensor, comprising at least one resonator, so as to determine the resonant frequency of said resonator, having a resonant frequency response defined by the design of said resonator, includes: a preliminary frequency-scan step for interrogating said resonator over a frequency range allowing for the rapid determination of a first resonant frequency (fr0) of said resonator by detecting the amplitude of the response signal of said resonator; a first step of a first couple of interrogations of said resonator at a first frequency (f11) and a second frequency (f21) such that: f11=fr0?fm/2 and f21=fr0+fm/2, fm being smaller than the width at half-maximum of the resonant frequency response defined by the design, allowing a first couple of amplitudes (Pf11, Pf21) of first and second reception signals to be defined; a second step of determining the amplitude difference (?(Pf11?Pf21)), said difference being signed; a third step allowing a first resonant frequency (fr1), contro

Abstract: The invention relates to a resonator of the high bulk acoustic resonator HBAR type, for operating at a pre-determined working frequency, comprising: a piezoelectric transducer (6), an acoustic substrate (10), a counter-electrode (8) formed by a metal layer adhering to a first face of the transducer (6) and a face of the acoustic substrate (10), and an electrode (4) arranged on a second face of the transducer (6) facing away from the first face of the transducer (6) and the substrate (10).

Abstract: The present invention relates to the field of acoustic wave devices, and particularly to that of transducers capable of operating at very high frequencies, from a few hundred MHz to several gigahertz, and its subject is more particularly an interface acoustic wave device including at least two substrates and a layer of ferroelectric material, the latter being contained between a first electrode and a second electrode and having first positive-polarization domains and second negative-polarization domains, the first and second domains being alternated, wherein the assembly constituted by the first electrode, the layer of ferroelectric material, and the second electrode is contained between a first substrate and a second substrate.

Abstract: Control of running conditions, and particularly physical parameters of tires are recommended to increase automobile safety. A sensor according to the invention is used to determine various factors such as the temperature or pressure of tires. The sensor is a hybrid resonant passive structure that may be integrated in the vehicle ground connection, and particularly in the rubber of the tire when it is manufactured.

Abstract: A remotely interrogatable passive sensor is provided. The sensor comprises an antenna and at least one surface wave resonator including a transducer with inter-digitated electrodes with two ports on the surface of a piezoelectric substrate, in which the antenna comprises conducting elements connected to the two ports and integrated onto said piezoelectric substrate. Advantageously, the antenna elements are folded on the substrate to enhance compactness. The passive sensor can be used for medical applications such as tissue analysis or arterial pressure measurement.

Abstract: The invention relates to a process for the collective fabrication of a remotely interrogable sensor having at least one first resonator and one second resonator. Each resonator exhibits respectively a first and a second operating frequency. A first series of first resonators are fabricated. The first resonators each have a first operating frequency belonging to a first set of frequencies centered on a first central frequency. A second series of second resonators are fabricated. The second resonators each having a second operating frequency belonging to a second set of frequencies centered on a second central frequency. A series of pairings of a first resonator and of a second resonator are conducted so as to form pairs of resonators exhibiting a difference of operating frequencies which is equal to the difference of the first and second central frequencies.

Abstract: The invention relates to a surface acoustic wave resonator produced on a cut substrate with propagation axes for which a nonzero directivity exists and comprising at least one central transducer (Tc) exhibiting a central axis, a first array of reflectors (R1) and a second array of reflectors (R2), said arrays being situated on either side of said transducer, characterized in that the two arrays of reflectors exhibit nonsymmetric configurations with respect to the central axis of said central transducer. The introduction of an asymmetry makes it possible to strongly attenuate the parasitic resonances which may appear when the resonators are produced notably on piezoelectric substrates of quartz type or any other material and cut with propagation axes for which there exists a natural directivity (LiTaO3, LiNbO3, langasite, GaPO4, LiB407, KNbO3, etc.

Abstract: Control of running conditions, and particularly physical parameters of tires are recommended to increase automobile safety. A sensor according to the invention is used to determine various factors such as the temperature or pressure of tires. The sensor is a hybrid resonant passive structure that may be integrated in the vehicle ground connection, and particularly in the rubber of the tire when it is manufactured.

Abstract: A bulk wave acoustic resonant structure which is in accordance with the invention allows the difficulties encountered at high frequency, the impossibility of working at low frequency on simple structures and the absence of an adequate coupling level to be overcome. The invention therefore proposes the use of an additional layer of material which covers the upper electrode of a piezoelectric transducer in order to localize the position of maximum intensity of the dynamic stress close to the centre of the piezoelectric layer through the effect of propagation. The structure that is in accordance with the invention may be associated with Bragg mirrors and various uses are presented.

Abstract: The invention relates to interfaces acoutics wave components made of lithium tantalate. Two substrate make up the filter have the same cut and the same crystal orientation, the invention gives the best cut angles in particular for optimizing the electromechanical coupling coefficient that determines the final performance characteristics of the component produced. Curves giving the variations of the coupling coefficient an the attenuation as a function of the cut angles and of the direction of propagation are provided. The values of the main acoustic characteristics of the component for these optimum cut angles are also given. The application of this type of device are, on the on hand, uses as a passive component such a resonator or a filter or a delay line, or as an integrated device, either in a measurement chain or in any array of devices operating according to the principle of recognition of the device by a phase code.

Abstract: The invention relates to interface acoustic wave components made of lithium tantalate. In the case in which the two substrates making up the filter have the same cut and the same crystal orientation, the invention gives the best cut angles in particular for optimizing the electromechanical coupling coefficient that determines the final performance characteristics of the component produced. Curves giving the variations of the coupling coefficient and the attenuation as a function of the cut angles and of the direction of propagation are provided. The values of the main acoustic characteristics of the component for these optimum cut angles are also given. The applications of this type of device are, on the one hand, uses as a passive component such a resonator or a filter or a delay line, or as an integrated device, either in a measurement chain or in an array of devices operating according to the principle of recognition of the device by a phase code.

Abstract: The invention relates to an acoustic wave device comprising a layer of ferroelectric material (C) and a substrate (S), characterized in that the layer of ferroelectric material lies between a first electrode (E1) which is deposited on the surface of the substrate or is a constituent part of the substrate and a second electrode (E2) and in that the layer of ferromagnetic material comprises positive first polarization domains (D1) and negative second polarization domains (D2)

Abstract: A low-loss surface acoustic wave filter on a quartz substrate with optimized cutting. A range of cutting angles and directions of propagation of the waves on the quartz substrate are defined, making it possible to obtain high coefficients of reflection of the electrodes used in the filter. The range of cutting angles and directions of propagation of the waves are decisive factors for the making of the filter.