70 results about "Elastic wave propagation" patented technology

The invention relates to the technical field of earthquake monitoring, and discloses a comprehensive earthquake prediction method, which comprises the following steps of: acquiring a continuous micro-motion data sequence to reconstruct an empirical green function sequence, and dividing the empirical green function sequence into a compression phase subset and a stretching phase subset by utilizing a synchronously acquired theoretical earth tide stress phase; respectively extracting a causal branch waveform corresponding to the positive time axis and a non-causal branch waveform corresponding to the negative time axis, and determining a weight index for inhibiting the non-structural interference by calculating a reciprocity residual error between a causal wave velocity offset and a non-causal wave velocity offset; correcting a wave velocity offset mean value by using the weight index to obtain a stress sensitivity coefficient reflecting the stress state of the earth crust medium; according to the method, a physical criterion is established by using an elastic wave propagation reciprocity principle, decoupling of medium attribute change and noise source spatial drift is realized, and visual wave velocity offset induced by environmental interference is eliminated.

The invention relates to the technical field of medical imaging, in particular to a biological tissue viscoelasticity measuring system and method.The system comprises an exciting unit, a measuring unit and a processing unit, the exciting unit excites biological tissue elastic vibration to repeatedly induce elastic waves through target radiation force; the imaging unit is used for performing optical coherence tomography scanning on elastic waves of the biological tissues and acquiring tissue vibration space distribution data of the biological tissues at different moments through scanning; and the analysis unit is used for reconstructing an elastic wave propagation process according to the tissue vibration space distribution data at different time, analyzing a phase velocity dispersion parameter of the elastic wave based on the elastic wave propagation process, and calculating the viscoelasticity of the biological tissue according to the phase velocity dispersion parameter. Therefore, the problem that related technologies can only be used for evaluating the retina elasticity and cannot measure the visco-elasticity of the retina is solved.

Provided is an elastic wave device capable of suppressing ripples near a resonance frequency. The elastic wave device (1) comprises a piezoelectric substrate (2) and an IDT electrode (7) disposed on the piezoelectric substrate (2). The piezoelectric substrate (2) comprises a high acoustic velocity layer and a piezoelectric layer (6). The IDT electrode (7) comprises first and second bus bars (14, 15) and a plurality of first and second electrode fingers (16, 17) alternately inserted into each other. First and second envelopes (A1, A2) which are imaginary lines formed by connecting the respective front ends of the plurality of first and second electrode fingers (16, 17) extend obliquely relative to the propagation direction of the elastic wave. A first dielectric film (9a, 9b) is disposed in at least one of a plurality of first gaps (G1) between the plurality of first electrode fingers (16) and the second bus bar (15) and a plurality of second gaps (G2) between the plurality of second electrode fingers (17) and the first bus bar (14), and the density of the first dielectric film (9a, 9b) is higher than that of silicon oxide.

This invention discloses a method for calculating the vibration response of a delaminated composite laminate, belonging to the field of structural defect calculation and analysis. The method includes: dividing the composite laminate with delamination defects into delaminated and intact regions based on the damage condition; decoupling the delaminated regions dynamically; describing the vibration characteristics of each component in both the delaminated and intact regions using elastic waves based on elastic wave propagation theory, and establishing vibration state vector expressions for each region; determining the compatibility relationship based on the displacement continuity and internal force equilibrium conditions at the coupling point between the delaminated and intact regions, and establishing structural dynamic equilibrium equations in wave space based on the boundary conditions of the composite laminate; solving the structural dynamic equilibrium equations to obtain the amplitudes of elastic waves of each order; and calculating the vibration response of each region of the composite laminate based on elastic wave theory and amplitude calculation. This invention solves the problem of low computational efficiency in existing methods.

The invention relates to a dynamic compaction construction intelligent monitoring and self-adaptive control method based on a physical information neural network, and the method comprises the steps: arranging a vibration sensor array in a construction safety region, collecting a compaction vibration signal in real time, and extracting time domain, frequency domain and spatial propagation characteristics; constructing a physical information neural network model, taking a soil elastic wave propagation equation as a physical constraint, taking vibration characteristics and monitoring point space coordinates as input, and predicting three-dimensional distribution of soil physical property parameters; based on the predicted soil body parameters, calculating the distribution and development trend of the bearing capacity of the foundation by adopting a Taisha foundation bearing capacity theory; a multi-target optimization model with the bearing capacity reaching the standard, the minimum energy consumption and the shortest time as targets is established, and follow-up tamping parameters are optimized; and construction is executed according to the optimized parameters, and data and model parameters are continuously updated. Compared with the prior art, the problems that in traditional dynamic compaction construction, the soil body state cannot be observed, and optimization lacks theoretical support are solved, and intelligentization and accurate control over the construction process are achieved.

The invention provides a mine acoustic emission source high-precision positioning method based on a finite element method. The method comprises the following steps: step 1, point source elastic wave propagation simulation based on the finite element method: step 101, constructing a three-dimensional space layered structure model; step 102, constructing a point sound source excitation model; step 103, setting a boundary condition and a low-reflection virtual domain; step 104, grid division; step 105, finite element simulation of point source elastic wave propagation; step 2, time difference inversion positioning: step 201, a probe arrangement strategy; step 202, waveform analysis and time difference information calculation; and step 203, carrying out inversion calculation on the sound source position. According to the method, the propagation process of sound waves in a three-dimensional layered space is simulated through a finite element method, advanced probe arrangement and an optimized positioning algorithm are combined, the problems that a traditional time difference positioning method is high in probe arrangement requirement and complex in calculation are solved, higher positioning precision and real-time performance are achieved, and the method is suitable for popularization and application. And the technical requirements of mine safety monitoring, water inrush early warning and rockburst prediction are met.

The scheme belongs to the technical field of structural mechanics, and discloses a metamaterial rod outputting only tensile waves and application thereof.The metamaterial rod comprises an even number of guide rods arranged symmetrically and a plurality of cells linearly arranged on the guide rods, each cell comprising a first connecting plate, a second connecting plate, a first inclined rod, a second inclined rod, a third inclined rod, a fourth inclined rod and a spring, and the stiffness of the first cell is smaller than that of the other cells.By utilizing external friction, the momentum conservation of the system is broken, and through in-depth analysis of the propagation mechanism of elastic waves, the metamaterial rod with uneven distribution is ingeniously designed, and the cells are unevenly arranged, so as to realize the unusual function of outputting only tensile waves.No matter whether an impact, a sudden stretching, a stretching or an alternating repeated load of stretching and compression is applied to one end of the rod, only the tensile signal is output at the other end of the rod, and the transmission of the tensile wave also exhibits the characteristics of a solitary wave, and the original wave shape and amplitude are maintained during the propagation process.

This defect inspection apparatus (100) is provided with an excitation unit (1), a laser illumination unit (2), an interference unit (30), an imaging unit (31), a holding member (4) for holding the imaging unit at a position spaced apart from an inspection target (90) by a predetermined distance, a connecting member (5) for connecting the holding member or the imaging unit and the excitation unit, and a controller (6) for generating an image (61) related to the propagation of an elastic wave on an inspection target.

This invention discloses a method for calculating the vibration response of a delaminated composite laminate, belonging to the field of structural defect calculation and analysis. The method includes: dividing the composite laminate with delamination defects into delaminated and intact regions based on the damage condition; decoupling the delaminated regions dynamically; describing the vibration characteristics of each component in both the delaminated and intact regions using elastic waves based on elastic wave propagation theory, and establishing vibration state vector expressions for each region; determining the compatibility relationship based on the displacement continuity and internal force equilibrium conditions at the coupling point between the delaminated and intact regions, and establishing structural dynamic equilibrium equations in wave space based on the boundary conditions of the composite laminate; solving the structural dynamic equilibrium equations to obtain the amplitudes of elastic waves of each order; and calculating the vibration response of each region of the composite laminate based on elastic wave theory and amplitude calculation. This invention solves the problem of low computational efficiency in existing methods.

Provided is an elastic wave device in which degradation in Q characteristics is less likely to occur. An elastic wave device (1) includes a piezoelectric substrate (2) and an IDT electrode (7) provided on the piezoelectric substrate (2), the IDT electrode (7) having an overlapping region in which a first electrode finger and a second electrode finger overlap along an elastic wave propagation direction, the overlapping region having a central region and first and second low sound velocity regions on both outer sides of the central region in the extension direction of the first and second electrode fingers, the first and second bus bars (11, 12) having a plurality of openings (11a, 12a), an inner bus bar portion (11b, 12b) on one side of the opening (11a, 12a) being connected to an outer bus bar portion (11c, 12c) on the other side through a plurality of connecting portions (11d, 12d), at least one of the plurality of connecting portions (11d, 12d) being a wide connecting portion (11d1, 12d1) having a width greater than the remaining connecting portions (11d, 12d).

The invention relates to an elastic wave device 10000 in the field of elastic wave-based components for areas such as telecommunication. The elastic wave device 1000 of the invention comprises a variable impedance means 1003, 2003, 3003, 10400, a first electromechanical device 3, 11130, in particular, a first transducer 3, 11130, and a second electromechanical device 5, 11140, in particular, a second transducer 5, 11140 or an electrode array configured to reflect at least partially elastic waves emitted by the first electromechanical device 3, an array 4000, 11150 of at least one electrode 1000, 2000, 3000 located between the first electromechanical device 3 and the second electromechanical device 5 in the direction of propagation of the elastic waves, and a temperature determination means 10200 configured to determine a temperature of an operating region of the elastic wave device.

The invention discloses an elastic wave device and an elastic wave device. The elastic wave device comprises a piezoelectric substrate and an electroacoustic transducer arranged above the piezoelectric substrate, the electroacoustic transducer comprises an IDT electrode and reflector electrodes arranged on the two sides of the IDT electrode. The IDT electrode comprises a plurality of first electrode fingers and a plurality of second electrode fingers which are arranged in parallel in a staggered mode, and a first bus bar and a second bus bar which are perpendicular to the extension direction of the first electrode fingers and the extension direction of the second electrode fingers and are arranged in parallel. The reflector electrode is provided with a fourth electrode finger; the length of the fourth electrode finger is set as beta, the length of the first electrode finger or the second electrode finger is set as alpha, and beta is larger than or equal to 5 alpha; the overlap length of the projection of the fourth electrode finger in the elastic wave propagation direction is alpha. The fourth electrode finger structure is arranged in the reflector, so that the pattern formed by the fourth electrode finger and the bus bar does not form a closed cavity, and the problems of difficulty in stripping and reliability caused by a closed gap in a traditional reflector are avoided.

A system (1) for characterizing tissue comprises: a probe for transmitting continuous and periodic mechanical vibrations (PMV) to tissue (51) of a subject; an ultrasonic transmitter for transmitting a sequence of ultrasonic beams (80, 80', 80") and an ultrasonic receiver for receiving corresponding echo signals to track how the tissue moves due to the periodic mechanical vibrations transmitted to the tissue; and a control module programmed to provide homogeneity information (808, 808', 808") to an operator of the system, the homogeneity information being determined based on at least some of the echo signals and representing the ability of the tissue to transmit elastic waves and the homogeneity of the tissue with respect to elastic wave propagation. A method for characterizing tissue is also provided.

Provided is an elastic wave device that is less likely to be surge-breakdown. A dielectric film (4) is provided so as to cover an IDT electrode (3) having: a first edge region (E1), a second edge region (E2), which are low sound velocity regions; and a first high sound velocity region (H1), a second high sound velocity region (H2), which are provided further outward than a crossing width region adjacent to a first electrode finger (13) and a second electrode finger (14) in an elastic wave propagation direction, and the thickness of the dielectric film (4) on the first edge region (E1), the second edge region (E2) is set to be thicker than the thickness of the dielectric film (4) on the first high sound velocity region (H1), the second high sound velocity region (H2).

This invention discloses a design and manufacturing method for a uniform cross-section explosive load simulator based on gradient elastic metamaterials, relating to the field of impact loading. Addressing the problems of high cost per use and the susceptibility of variable cross-section elastic rods to local buckling instability under high-speed impact leading to waveform distortion in existing simulators, this invention, while maintaining the macroscopic uniform cross-section shape of the simulator, derives the ideal wave impedance gradient required to achieve the target explosive load based on the one-dimensional elastic wave propagation inverse design theory; establishes the mapping relationship between the relative density of a three-period minimal surface (TPMS) metamaterial unit cell and its equivalent mechanical parameters, and inversely solves the spatial relative density distribution function; extracts the waveform through dynamic impact finite element simulation, and introduces an impedance gradient correction factor to perform nonlinear iterative correction of the density function, obtaining a final three-dimensional metamaterial geometric model that accurately matches the waveform, and uses a flexible polymer material for additive manufacturing. This invention achieves the purely elastic, non-destructive, and reusable simulator, perfectly adapting to the stable firing of light gas cannons, and exhibiting excellent anti-instability capability and waveform fidelity under strong dynamic loads.

Provided is an elastic wave device that can suppress an IMD and can suppress deterioration of reception sensitivity. An elastic wave device (1) includes a piezoelectric substrate (2), a first IDT electrode (3), reflectors (4A, 4B) provided on both sides of the first IDT electrode (3) in an elastic wave propagation direction, and a second IDT electrode (5) provided so as to sandwich the reflector (4A) and oppose the first IDT electrode (3) and constitute a second IDT (5A). The first and second IDT electrodes (3, 5) have a plurality of electrode fingers that overlap each other in the first and second intersection regions (A, B) in the elastic wave propagation direction. The first and second intersection regions (A, B) overlap each other in the elastic wave propagation direction. A third bus bar (16) of the second IDT electrode (5) is connected to a first bus bar (12) of the first IDT electrode (3), and a fourth bus bar (17) of the second IDT electrode (5) is connected to a ground potential. A resonance frequency of a portion including the second IDT electrode (5) is included in a frequency band of an interference wave signal.

Provided is an elastic wave device with low loss. In an elastic wave device (1), an IDT electrode (6) and a reflector electrode (7, 8) are provided on a piezoelectric substrate (2), an area in which first electrode fingers (6c) and second electrode fingers (6d) of the IDT electrode (6) overlap in an elastic wave propagation direction is a crossover area (K), the crossover area (K) has a central area (C), and first edge areas (E1) and second edge areas (E2) on both sides of the central area (C), and a dielectric film (9, 10) is arranged to pass through the reflector electrode (7, 8) from the first edge areas (E1) and the second edge areas (E2) to an area outside the elastic wave propagation direction of the reflector electrode (7, 8).

The application relates to the technical field of building health monitoring, and discloses a building health state monitoring method based on vibration signals. The method collects vibration data of different monitoring points of a building, and obtains external influence data such as meteorological data, traffic data, underground water level data, construction activity data and earthquake activity data; after uniform time calibration and preprocessing of the above data, natural frequency, vibration energy, cepstrum, three-dimensional vibration trajectory, ground reflection wave, elastic wave propagation and external influence characteristics are extracted; the extracted characteristics are input into a building evaluation model to obtain health state evaluation results including a health index, an abnormal type and a risk level; further combined with evaluation results and spatial position relationships of buildings in a target region, a group abnormal linkage relationship is identified, regional synchronous abnormality, single-body abnormality or conduction abnormality is determined, and regional safety evaluation results and risk early warning information are generated. The method improves the accuracy and early warning timeliness of building and building group health monitoring.

This elastic wave device comprises a substrate including an end surface and having a piezoelectric body, and a plurality of strip electrodes located above the substrate and each extending in parallel to each other, wherein: at least a portion of the plurality of strip electrodes is an excitation part capable of exciting an elastic wave; the end surface is parallel to the extending direction of the strip electrodes in plan view and is located in an elastic wave propagation direction with respect to the excitation part; the plurality of strip electrodes includes a first strip electrode located closest to the end surface side in the elastic wave propagation direction and a second strip electrode farther from the end surface than the first strip electrode in the elastic wave propagation direction; the second strip electrode is the excitation part; and the average thickness of the first strip electrode in a cross section cut in the elastic wave propagation direction is less than the average thickness of the second strip electrode.

A filter device capable of realizing an increase in the amount of attenuation outside a passband. A filter device (1) has a filter circuit (3) with a plurality of series arm resonators (S1-S4) connected between a first terminal (2a) and a second terminal (2b), the series arm resonators (S1-S4) having at least two series arm resonators (S1, S3) with different anti-resonance frequencies from each other, and an additional circuit (4) connected in parallel with the filter circuit (3) between the first terminal (2a) and the second terminal (2b), the additional circuit (4) having at least three IDT electrodes (5-8) arranged along an elastic wave propagation direction, the at least three IDT electrodes (5-8) having an IDT electrode (7) connected to the filter circuit (3) on the first terminal (2a) side and IDT electrodes (5, 6, 8) connected to the filter circuit (3) on the second terminal (2b) side, the IDT electrode (7) being connected to a first node (N1) which is one end of the series arm resonator (S3) having the lowest anti-resonance frequency, the IDT electrode (5) being connected to a second node (N2) which is one end of the series arm resonators (S1, S2) other than the series arm resonator (S3) and different from the first node (N1), and the IDT electrode (8) being connected to a third node.

A multiplexer (1) is provided with a first filter (10) and a second filter (50) having a passband on a lower frequency side than the passband of the first filter (10). The longitudinal coupling elastic wave resonator (13) of the first filter (10) has an IDT electrode group (30) including a plurality of IDT electrodes (31 to 37). The IDT electrode group (30) has an asymmetric shape with reference to a center line (CL) passing through the center (Cl) of the IDT electrode group (30) and orthogonal to the elastic wave propagation direction (D1). From the longitudinal coupling elastic wave resonator (13), the IDT electrodes (32, 34, 36) connected to the first path (rl) on the side of the common terminal (Tc) have a total average of electrode finger spacings (pt) smaller and a total of electrode finger numbers (pn) fewer than the IDT electrodes (31, 33, 35, 37) connected to the first path (rl) on the side of the first terminal (Tl).

The present invention provides an elastic wave device capable of suppressing transverse modes and high-order modes. The elastic wave device (1) of the present invention comprises a piezoelectric substrate (2) and an IDT electrode (7). The IDT electrode (7) comprises a central region (C) and a first edge region (E1) and a second edge region (E2). The regions including the first edge region (E1) and the second edge region (E2) and overlapping with the regions in the direction of propagation of the elastic wave are the first extended edge region (Ex1) and the second extended edge region (Ex2). The first extended edge region (Ex1) and the second extended edge region (Ex2) are provided with a first sound velocity adjustment portion (L) and a second sound velocity adjustment portion (M) having a lower sound velocity than the central region (C). The first sound velocity adjustment portion (L) comprises a first end portion (La) and a second end portion (Lb), and the second sound velocity adjustment portion (M) comprises a third end portion (Ma) and a fourth end portion (Mb). The first end portion (La) to the fourth end portion (Mb) are located outside the first edge region (E1) and the second edge region (E2). At least one of the two sets of ends, the first end portion (La) and the third end portion (Ma) and the second end portion (Lb) and the fourth end portion (Mb), do not overlap in the direction in which the plurality of electrode fingers extend.

The invention provides a neural network training method, a model construction method, devices, equipment and a medium, when a two-phase medium fluctuation feature learning network is trained, reservoir physical property parameters are used as input, a plurality of prediction wave equation coefficients of a sample two-phase pore medium elastic wave propagation model are predicted, and the two-phase medium fluctuation feature learning network is trained by combining a physical constraint mechanism based on plane wave analysis. According to error loss between predicted frequency dispersion attenuation characteristics and real frequency dispersion attenuation characteristics of a sample biphase pore medium elastic wave propagation model, parameters of a biphase medium fluctuation characteristic learning network are adjusted, and the network is made to have higher prediction stability and physical consistency through back propagation; the prediction wave equation coefficient output by the two-phase medium fluctuation feature learning network is ensured, and meanwhile, the data precision and physical consistency requirements are considered, so that the physical consistency, the expression accuracy and the generalization ability of the constructed target two-phase pore medium elastic wave propagation model are improved.

An elastic wave device includes a substrate having an end surface and including a piezoelectric body, and strip electrodes located above the substrate, each of the strip electrodes extending in parallel. Some of the strip electrodes are excitation portions that can excite an elastic wave, the end surface is parallel to the direction the strip electrodes extend, and located in an elastic wave propagation direction. The plurality electrodes include a first strip electrode located closest to the end surface in the elastic wave propagation direction, and a second strip electrode farther from the end surface than the first strip electrode in the elastic wave propagation direction, the second strip electrode is the excitation portion, and an average thickness of the first strip electrode is smaller than an average thickness of the second strip electrode, in a cross section cut in the elastic wave propagation direction.

There is a need to reduce spurious emissions from elastic wave equipment. [Solution] The elastic wave device includes a substrate having a piezoelectric material and an end face, and a plurality of strip electrodes located above the substrate and each extending in parallel, wherein at least some of the plurality of strip electrodes are excitation sections capable of exciting elastic waves, the end face is parallel to the direction in which the strip electrodes extend when viewed from above in plan view, and is located in the elastic wave propagation direction relative to the excitation section, the plurality of strip electrodes include a first strip electrode located closest to the end face in the elastic wave propagation direction, and a second strip electrode which is further from the end face than the first strip electrode in the elastic wave propagation direction and is the excitation section, in a cross section cut in the elastic wave propagation direction, the average thickness of the first strip electrode is smaller than the average thickness of the second strip electrode, the substrate has a groove on its upper surface, and the end face is part of the side surface of the groove.

The present invention provides an elastic wave device that suppresses transverse modes and reduces energy leakage of elastic waves. [Solution] The elastic wave apparatus comprises a piezoelectric substrate including a piezoelectric layer and an IDT electrode 9 having a plurality of first floating electrodes 11. The intersection region A has a central region F located on the central side in the propagation orthogonal direction perpendicular to the elastic wave propagation direction, and a first edge region H1 and a second edge region H2 facing each other with the central region F in between. The plurality of first floating electrodes 11 are located between the first edge region H1 and the first bus bar 13. The region located between the first edge region H1 and the first bus bar 13, where the plurality of first floating electrodes 11 are provided, is the first floating electrode formation region U1. The elastic wave apparatus further comprises a first mass addition film 8A provided in the first edge region H1 and a second mass addition film 8B provided in the first floating electrode formation region U1.

The invention discloses a local MQRBF-FD elastic wave propagation simulation method based on multi-scale modeling and parallel optimization. The method comprises the following steps: 1, based on sine function combination characteristics of elastic wave Fourier expansion, optimizing shape parameters of an MQRBF by adopting a parallel improved random walk algorithm, and training an Adam-BP neural network model; 2, dividing a computational domain into a plurality of local sub-domains, and completing high-precision spatial discretization of a wave field in each sub-domain; 3, discretizing time by adopting a finite difference method, and finishing time integration in combination with a central difference method; and 4, converting wave field evolution into a solving problem of a sparse linear equation set, and updating a global wave field value through efficient iteration to complete high-precision simulation of elastic wave propagation. According to the method, the precision and calculation efficiency of elastic wave propagation simulation in the complex heterogeneous medium are remarkably improved, and the problems that a traditional finite difference method is large in numerical error and low in calculation efficiency under the complex boundary condition and the heterogeneous medium are effectively solved.

The invention relates to the technical field of optical imaging, in particular to an endoscopic imaging device based on a forward probe, a medical host system and an imaging method.The endoscopic imaging device comprises a forward scanning probe, an in-vitro system, an excitation unit and a signal processing unit, receiving an optical signal carrying tissue scattering information; the in-vitro system is used for realizing light interference, converting an interference light signal into digital OCT original data, outputting a synchronous trigger signal to the excitation unit, collecting an OCT scattering signal in an elastic wave propagation process, converting the OCT scattering signal into an OCT complex value signal, and packaging the OCT complex value signal into an original data stream; and the signal processing unit performs phase extraction, displacement calculation or wave velocity estimation and the like on the original data stream, performs elastic inversion, and outputs tissue elastic information in all directions, so that the problems of limited imaging view field, insufficient lesion recognition sensitivity, limited clinical application, elastic quantitative measurement and the like in related technologies are solved, and the accuracy and the reliability of the system are improved. And the accuracy and the sensitivity of early lesion diagnosis are improved.

A force transmission structure (100), a packaging assembly (400), an electric appliance assembly, a filter screen cover and a household appliance, the force transmission structure (100) comprises a bottom plate (200), and the bottom plate (200) is provided with a regular polygonal through hole (300). The packaging assembly (400) comprises a plurality of protection pieces (401), at least one protection piece (401) is provided with a force transmission structure (100), structural damage caused by energy accumulation near the corner or damage to the product caused by excessive elastic waves propagating into the foam body can be avoided, and therefore the packaging assembly (400) can be designed through extremely thin packaging buffering materials. Therefore, the use amount of packing materials can be reduced, the packing size is reduced, the container loading capacity is improved, and the marine transportation cost is reduced.

Provided is an elastic wave device in which response caused by Rayleigh waves is suppressed. An elastic wave device (1) includes: an IDT electrode (5) provided on a piezoelectric substrate; and reflector electrodes (6, 7) disposed on both sides of the elastic wave propagation direction of the IDT electrode (5) and having a plurality of electrode fingers (6a or 7a) disposed at intervals, and further includes: dielectric films (10, 11) disposed between the reflector electrodes (6, 7) and the piezoelectric substrate in regions in which the plurality of electrode fingers (6a, 7a) of the reflector electrodes (6, 7) and the intervals are provided.