摘要:
An acoustic wave bandpass filter comprises at least an input first acoustic wave resonator with an output surface, and an output second acoustic wave resonator with an input surface, said resonators being coupled to each other along a set direction, the input and output surfaces being substantially opposite, and at least one first phononic crystal structure between said input and output resonators and/or a second phonic crystal structure at the periphery of said resonators so as to guide the acoustic waves, generated by said input resonator, toward said output resonator along said set direction, the resonators ensuring an impedance conversion and/or a mode conversion.
摘要:
An acoustic structure comprising comprises a layer of material having a first Young's modulus called the intrinsic modulus and a first density called the intrinsic density, characterized in that the layer comprises at least one first zone having said first Young's modulus and said first density and at least one second zone buried in the volume of said layer of material and having a second Young's modulus and/or a second density obtained by implanting and/or by diffusing atoms into the volume of said layer.
摘要:
An acoustic wave bandpass filter comprises at least two bulk acoustic wave resonators, laterally coupled to each other acoustically, each resonator including a film of piezoelectric material and at least a first electrode and/or a second electrode, said bulk waves propagating in a direction perpendicular to the plane of the film of piezoelectric material, characterized in that: it further comprises at least a first phononic crystal structure between said resonators such that the transmission coefficient of the lateral acoustic waves can be decreased in a direction parallel to the plane of the piezoelectric film; and the first phononic crystal structure is formed in a matrix of dielectric material or with patterns made from dielectric material.
摘要:
A process for producing an acoustic device having a phononic crystal structure comprising inclusions produced in a first medium distributed in a matrix of a second medium, to block propagation of acoustic waves within a bandgap frequency band, includes: defining geometric parameters of said inclusions, which have walls contacting said matrix, making at least one non-zero first wall angle, to the normal of the plane of said structure, said geometric parameters including said first wall angle; determining a function relating to variation in frequency position of said bandgap with said wall angle or relating to variation in width of said bandgap with said wall angle; determining said at least first angle, for a selected frequency position and/or selected width of the bandgap, from the function or functions determined beforehand; and producing said inclusions having at least said first wall angle in said matrix formed by said second medium.
摘要:
An acoustic structure comprising comprises a layer of material having a first Young's modulus called the intrinsic modulus and a first density called the intrinsic density, characterized in that the layer comprises at least one first zone having said first Young's modulus and said first density and at least one second zone buried in the volume of said layer of material and having a second Young's modulus and/or a second density obtained by implanting and/or by diffusing atoms into the volume of said layer.
摘要:
An acoustic wave bandpass filter comprises at least an input first acoustic wave resonator with an output surface, and an output second acoustic wave resonator with an input surface, said resonators being coupled to each other along a set direction, the input and output surfaces being substantially opposite, and at least one first phononic crystal structure between said input and output resonators and/or a second phonic crystal structure at the periphery of said resonators so as to guide the acoustic waves, generated by said input resonator, toward said output resonator along said set direction, the resonators ensuring an impedance conversion and/or a mode conversion.
摘要:
An electrical signal combiner includes at least one first element and a second element respectively connected to a first input port and to a second input port, and a third element connected to an output port, the electrical signals being propagated between the input and output ports. The combiner includes a medium; and the first, second and third elements are acoustic wave transducers, the electrical signals being carried by acoustic waves propagated between the input and output ports within the medium. Advantageously, the first transducer and the third transducer are separated by an acoustic distance of (2k+1)λ/4 with k an integer greater than or equal to 0 with λ the acoustic propagation wavelength; the second transducer and the third transducer are separated by an acoustic distance of (2k′+1)λ/4 with k′ an integer greater than or equal to 0; and the first and second transducers are separated by an acoustic distance of (2k″+2)λ/4 with k″ an integer greater than or equal to 0—in such a manner as to, on the one hand, generate constructive interference at the output port and, on the other hand, to isolate the first and second input ports by destructive interference of acoustic waves at the ports.
摘要:
A guided acoustic wave resonant device is provided. The device comprises at least two filters (F1, . . . , Fi, . . . , FN), each filter comprising at least two acoustic wave resonators (R11- R12, . . . , Ri1-Ri2, . . . , RN1-RN2), each filter having a useful frequency band (BF1, . . . , BFi, . . . , BFN) centred on a central frequency (f1, . . . , fi, . . . , fN), each resonator comprising at least one suite of inter-digitated upper electrodes exhibiting a periodic structure of period (Λij) and a layer of piezoelectric material, each resonator having a coupling coefficient (k21, k22, . . . , k2n) and a resonant frequency (fr1, . . . , fr2, . . . , fN), wherein at least one of the resonators comprises a differentiation layer (CDfi) making it possible in combination with the period of the inter-digitated electrodes to modify the coupling coefficient of the said resonator, the useful band and the central frequency being determined by the resonant frequencies and the coupling coefficients of the resonators which are adapted so as to have a determined useful bandwidth.
摘要:
An electromechanical device having a resonator using acoustic waves propagating laterally within a piezoelectric plane resonant structure and electrodes on a face of said structure. The resonant structure comprises: a transduction region having a transduction length and generating acoustic waves; a free propagation region for the acoustic waves, adjacent to the transduction region and defined the plane of the transduction region; the resonant structure length being equal to an integer number of half-wavelengths, the resonance frequency of said resonator equaling the average propagation velocity of the wave within the structure divided by said wavelength, to adjust the quality factor of the resonator fixed by the length of the resonant structure and the coupling coefficient fixed by the ratio of the transduction length over the length of the resonant structure; the resonant structure defined by the assembly of the transduction region and the propagation region being laterally bounded by reflection regions.
摘要:
An electrical signal combiner includes at least one first element and a second element respectively connected to a first input port and to a second input port, and a third element connected to an output port, the electrical signals being propagated between the input and output ports. The combiner includes a medium; and the first, second and third elements are acoustic wave transducers, the electrical signals being carried by acoustic waves propagated between the input and output ports within the medium. Advantageously, the first transducer and the third transducer are separated by an acoustic distance of (2k+1)λ/4 with k an integer greater than or equal to 0 with λ the acoustic propagation wavelength; the second transducer and the third transducer are separated by an acoustic distance of (2k′+1)λ/4 with k′ an integer greater than or equal to 0; and the first and second transducers are separated by an acoustic distance of (2k″+2)λ/4 with k″ an integer greater than or equal to 0—in such a manner as to, on the one hand, generate constructive interference at the output port and, on the other hand, to isolate the first and second input ports by destructive interference of acoustic waves at the ports.