89 results about "Antiresonance" patented technology

The invention discloses an intelligent control method and system for a motor driver, and the method comprises the steps: building an acoustoelectric incidence matrix through collecting harmonic current and sound pressure fluctuation data in the operation process of a motor, and forming a fault feature library; identifying an available fault mode to determine an energy collection point, and performing phase deviation processing on the collection point to generate an auxiliary driving signal; performing spectrum analysis on the sound pressure fluctuation data to obtain an acoustic characteristic spectrum, extracting an efficiency indication tone through characteristic decomposition, mapping the efficiency indication tone into a torque optimization parameter, and establishing a noise reduction control table; performing spectrum analysis on the enhanced control domain to identify a high-energy frequency band, executing a frequency shift operation to generate a safety frequency band signal, and forming a multi-frequency band management strategy in combination with a noise reduction control table; a management strategy is decomposed into parallel control flows for sequential staggered arrangement, and an energy-saving control matrix is generated; and generating a PWM control signal based on the matrix, carrying out edge reconstruction, and obtaining a softened edge waveform through an anti-resonance injection technology to complete intelligent control of the motor driver.

The utility model discloses a surface acoustic wave device and a radio frequency front-end module. The surface acoustic wave device comprises an interdigital transducer, wherein the interdigital transducer comprises a first bus bar and a second bus bar which are oppositely arranged, an electrode finger and a plurality of gap electrodes; in the extending direction of the electrode fingers, an overlapping area is formed between the first bus bar and the second bus bar, a first area is formed between the overlapping area and the first bus bar, a second area is formed between the overlapping area and the second bus bar, and the first area and the second area are adjacent to the first bus bar and the second bus bar respectively; the plurality of gap electrodes are arranged in at least one of the first area and the second area, and the plurality of gap electrodes, the bus bars and the electrode fingers are arranged at intervals; wherein the plurality of gap electrodes form a first curve in the arrangement direction of the electrode fingers. According to the invention, the Q value near the anti-resonance point can be improved while the inhibition effect of the transverse mode is improved.

The invention relates to an optronic sight having a critical mode, in particular an anti-resonance mode, comprising a variable fundamental frequency, and to a motorised vehicle comprising such a sight. This optronic sight for a motorised vehicle such as an aerial, marine or land vehicle, comprises: - a sighting module (13) capable of being moved about a first axis (X) and a second axis (Y) which is not parallel to the first axis; - means (14, 15) for moving the sighting module about the first axis and the second axis; and - a servo loop for slaving a position parameter of the sighting module to a setpoint, comprising an adaptive servo corrector (16) capable of calculating a command for a controlled device having a critical mode modifying the response of the device. The sight comprises means (23) capable of determining a fundamental frequency of the variable critical mode on the basis of an operating parameter of the controlled device, the corrector (16) being calculated from the fundamental frequency determined to compensate for the anti-resonance or resonance mode.

The invention relates to the technical field of communication equipment design, in particular to a design method and system for a broadband annular magnetoelectric antenna with a high electromechanical coupling coefficient. Constructing a vibration analysis model of the annular piezoelectric layer, and calculating to obtain a characteristic equation of rigidity and mass coefficients according to the vibration analysis model; solving the characteristic equation of the rigidity and the quality coefficient to obtain a resonant frequency and an anti-resonant frequency; the resonant frequency and the anti-resonant frequency are substituted into an electromechanical coupling coefficient formula, a size factor is introduced, and a correction formula is constructed; obtaining an optimized size parameter of the annular piezoelectric layer based on a correction formula; optimized size parameters of the annular piezoelectric layer can be obtained through simulation, the design efficiency and the performance stability of the antenna are further improved, and in practical application, the antenna can adapt to the requirements of different frequency bands and scenes more quickly.

The invention relates to the technical field of radio frequency, in particular to a pressure detection method and device based on a single surface acoustic wave resonator and a storage medium, and the method comprises the steps: S1, obtaining the temperature sensitivity coefficient information and strain sensitivity coefficient information of the resonant frequency and anti-resonant frequency of a piezoelectric substrate; s2, determining a target tangential range according to the temperature sensitivity coefficient information and the strain sensitivity coefficient information; s3, calculating and determining a strain-frequency incidence relation based on the target tangential range; and S4, detecting and determining pressure information according to the strain-frequency association relationship. Through the resonant frequency information and the anti-resonant frequency information of the piezoelectric substrate, pressure inspection and temperature compensation are realized, and only one resonator is needed, so that the overall size of the device is small, and the problem that the temperatures of a multi-resonator structure are different does not exist.

Anti-resonance element preform for producing an anti-resonant hollow-core fiber includes a first longitudinal axis, an ARE outer element designed in a circular arc-like manner, and an ARE inner element. The ARE outer element and the ARE inner element are connected to one another along two connecting lines, which are arranged essentially in parallel to the first longitudinal axis. The ARE outer element has an inner space, which is at least partially limited by an ARE outer wall and into which the ARE inner element, designed in a circular arc-like manner, protrudes at least partially.

The invention relates to a design method of a double-end-pair resonance type surface acoustic wave filter, which comprises the following steps of: determining a core structure component of the double-end-pair resonance type surface acoustic wave filter, comprising a piezoelectric substrate, an input transducer, an output transducer and a reflecting grating; a two-dimensional model of a pair of interdigital transducers is established by using COMSOL software based on the wavelength of the interdigital transducers, the resonant frequency and the anti-resonant frequency are simulated by changing the thickness of the interdigital transducers, the appropriate film thickness of the interdigital transducers is selected, the simulation propagation velocity of the interdigital transducers is obtained according to the resonant frequency and the anti-resonant frequency corresponding to the thickness, and the simulation propagation velocity of the interdigital transducers is calculated. Extracting equivalent circuit model parameters of the double-end pair resonant surface acoustic wave filter, performing ADS software simulation, determining the number of reflecting grating fingers, performing experimental verification, obtaining an actual center frequency and an actual propagation speed, comparing the actual center frequency with a target center frequency, if the actual center frequency is not matched with the target center frequency, repeating the operation, and if the actual center frequency is not matched with the target center frequency, repeating the operation. And the actual center frequency coincides with the target center frequency.

The invention relates to a transverse excitation bulk acoustic wave resonator with an embedded electrode structure, which belongs to the technical field of radio frequency communication and comprises a substrate, a temperature compensation layer and a piezoelectric layer which are arranged in at least one of the following layouts: (1) the temperature compensation layer and the piezoelectric layer are sequentially formed on the substrate; a groove array is etched on one side, deviating from the temperature compensation layer, of the piezoelectric layer; (2) the piezoelectric layer and the temperature compensation layer are sequentially formed on the substrate, and a groove array is etched on one side, close to the temperature compensation layer, of the piezoelectric layer and on the temperature compensation layer; the transverse excitation bulk acoustic wave resonator further comprises an embedded electrode structure and a cavity, and the embedded electrode structure is formed in the groove array so as to suppress a stray mode; the cavity is formed in the substrate. Compared with the prior art, the resonator provided by the invention can effectively suppress a stray mode, so that an admittance curve between a resonant frequency (fr) and an anti-resonant frequency (fa) is smoother.

A bandpass filter is provided, comprising a series resonator circuit disposed between an input and an output of the bandpass filter; a first shunt resonator circuit connected to ground in parallel with the series resonator circuit; and a second shunt resonator circuit connected to ground in parallel with the series resonator circuit, the second shunt resonator circuit configured to have one or more frequency pairs comprising an antiresonant frequency and a first resonant frequency, wherein for each frequency pair the antiresonant frequency is within a passband of the bandpass filter and the first resonant frequency at a higher frequency than the antiresonant frequency. A radiofrequency module and a wireless device comprising the same are also provided.

A method for producing an anti-resonant hollow-core fiber having an outer diameter of less than 500 mm, having the steps of: providing a sheath tube, which comprises a sheath tube inner bore and a sheath tube longitudinal axis along which a sheath tube wall extends, the sheath tube wall being delimited by a sheath tube inner face and a sheath tube outer face; preparing a number of anti-resonance units, each comprising an ARU outer tube; inserting at least parts of the anti-resonance units into the sheath tube inner bore; and creating a hollow-core assembly comprising the sheath tube and the anti-resonance units by at least partially connecting the anti-resonance units to the sheath tube inner face; preparing a jacket tube, which comprises a jacket tube inner bore and a jacket tube longitudinal axis along which a jacket tube wall extends.

Described herein is a method of estimating a quantity dependent on a capacitance (Cf) of an electrical filter connected to an AC side of an electrical converter. The method includes injecting a plurality of frequency components into a voltage reference of the electrical converter; operating the electrical converter with the voltage reference by determining switching commands from the voltage reference and applying the switching commands to the electrical converter; determining an AC side voltage (uc) and an AC side current (ic) in the AC side of the electrical converter and determining a filter admittance and / or filter impedance from the AC side voltage (uc) and the AC side current (ic); determining at least one of a resonance frequency and an anti-resonance frequency of the electrical filter; and determining the quantity dependent on the capacitance (Cf) of the electrical filter from the resonance frequency and / or the anti-resonance frequency.

The application provides a film bulk acoustic resonator, comprising a substrate, an acoustic reflection structure arranged on one side of the substrate, a bottom electrode arranged on one side of the acoustic reflection structure, a piezoelectric film covering the bottom electrode, and a top electrode arranged on the side of the piezoelectric film away from the bottom electrode, wherein the side of the top electrode away from the piezoelectric film is provided with an interdigital protruding frame, the interdigital protruding frame comprises oppositely arranged first and second protruding frames, at least one pair of interdigital structures are formed by extending the first and second protruding frames towards each other and being spaced apart by a preset distance and being overlapped, and each interdigital structure comprises two interdigital structures spaced apart by a preset distance along the overlapping direction. The application can reflect two or more transverse Rayleigh-Lamb waves to achieve high reflection efficiency and improve the Q value corresponding to the anti-resonance frequency of the resonator. The peeling residue problem caused by the closed loop of the existing protruding frame can be improved.

The embodiment of the invention discloses a surface acoustic wave resonator, a surface acoustic wave filter and a multiplexer. The surface acoustic wave resonator includes: a piezoelectric layer; a conductive layer; the conductive layer comprises a first conductive unit and a second conductive unit; the first conductive unit comprises an interdigital transducer electrode, and a first bus bar and a second bus bar which are arranged at two ends of the interdigital transducer electrode; the interdigital transducer electrode comprises a plurality of first long electrode fingers and a plurality of second long electrode fingers which are alternately arranged in the first direction and extend in the second direction. Wherein in the second direction, at least one pair of adjacent first long electrode fingers are in short circuit on the side away from the first bus bar, and the second long electrode finger located between the two short-circuit first long electrode fingers is arranged in a suspended mode to form a suspended finger. The second conductive unit comprises a first reflecting grating and a second reflecting grating. According to the technical scheme, the distance between the resonance point and the anti-resonance point of the resonance unit can be shortened. The surface acoustic wave resonator is applied to a surface acoustic wave filter and can improve pass band edge roll-off.

The objective of the present invention is to provide, in order to solve the described problems, a surface acoustic wave (SAW) resonator capable of adjusting singular points through a phase change of a surface acoustic wave, and a manufacturing method therefor, the SAW resonator changing the phase of a SAW generated and propagated in an IDT electrode unit of the SAW resonator, so as to intentionally adjust singular points, that is, a resonance frequency and an anti-resonance frequency according to desired design specifications, even if a capacitor is not additionally connected to the SAW resonator while an area of the SAW resonator is maintained as is, thereby enabling skirt characteristics of a SAW pass filter including the SAW resonator to be more sharply improved according to the design specifications.

Acoustic wave filters operating at wider passband with enhanced frequency response are provided herein. In certain embodiments, an acoustic wave filter comprises an input port and an output port, a plurality of series resonators electrically connected in series between the input port and the output port, the plurality of series resonators including a first group of resonators and a second group of resonators, each resonator of the first group of resonators having a raised frame region, the second group of resonators including at least one resonator having its resonance frequency closest to one edge of a target passband that is closer to its anti-resonance frequency lacking any raised frame region such as to broaden a bandwidth of the target passband, and a plurality of shunt resonators each being electrically connected between respective series resonators and a ground.

The application discloses a kind of based on low-loss anti-resonance hollow waveguide broadband high-efficiency leaky-wave antenna design method and structure, its technical scheme includes: first based on anti-resonance principle design single dielectric wall hollow waveguide;Further introduce second dielectric wall optimization form double dielectric wall anti-resonance hollow waveguide, significantly enhance the transverse restraint to electromagnetic energy in air cavity by cascading reflection effect, realize super low loss transmission;Finally, etching periodic radiation slot in the upper layer metal plate of double dielectric wall hollow waveguide, construct leaky-wave antenna with frequency scanning function.The application uses air as main transmission medium, fundamentally reduces dielectric loss, so that the antenna has ultra-low transmission loss and ultra-high radiation efficiency in wide frequency band, while the structure is simple, process compatibility is strong, only through standard PCB process can be realized, can be widely used in 5G / 6G communication, millimeter wave radar, terahertz imaging and other high-performance wireless systems.

Filter chip comprehensive - a continuous carrier substrate, - at least one electrical filter (1) of the first type is on the carrier substrate, which comprises at least one SAW resonator (10) of the first type, wherein - the SAW resonator (10) of the first type comprises a piezoelectric layer (11), an intermediate layer (12) on the piezoelectric layer (11) and an interdigital electrode structure (13) on the intermediate layer (12), - the interdigital electrode structure (13) is separated from the piezoelectric layer (11) by the intermediate layer (12), and wherein - the intermediate layer (12) is made of a dielectric, non-piezoelectric material; wherein the intermediate layer (12) is applied to the piezoelectric layer (11) in such a way that a distance between a resonance and an anti-resonance of the electrical filter of the first type is reduced; and - a plurality of electrical filters (2) of a second type on the carrier substrate, each comprising at least one SAW resonator (20) of a second type, wherein - the second type SAW resonator (20) comprises a piezoelectric layer (11) and an interdigital electrode structure (13) which is applied directly to the piezoelectric layer (11).

The present invention relates to the field of microelectronics technology, and in particular to a high-order acoustic wave filter and a communication device using the same. The high-order acoustic wave filter provided by the present invention includes at least one series resonator and at least one parallel resonator; the resonator in the high-order acoustic wave filter includes a supporting substrate, a bottom electrode, a piezoelectric film and a top electrode arranged in sequence from bottom to top; the top electrode is a forked electrode; the target mode of the resonator is a high-order acoustic wave mode generated by excitation of a longitudinal electric field; by making the product of the electrode finger spacing of the top forked electrode of some resonators and the anti-resonance frequency greater than the slow shear wave sound velocity of the supporting substrate, and making all resonators meet the product of the electrode finger spacing of the forked electrode and the upper cutoff frequency of the filter less than the fast shear wave sound velocity of the supporting substrate, it is possible to not only reduce the influence of the parasitic mode of the resonator, but also ensure that the passband of the filter is almost unaffected.

The invention relates to a signal-energy co-transmission hollow-core optical fiber and a preparation method, the signal-energy co-transmission hollow-core optical fiber comprises a communication transmission unit and an optical energy transmission unit, the communication transmission unit comprises an outer cladding, the outer cladding is internally provided with a plurality of communication fiber cores and a plurality of positioning fiber cores, and the positioning fiber cores are uniformly arranged along the circumference of the outer cladding; the optical energy transmission unit comprises a plurality of anti-resonance units connected with the inner wall of the outer cladding, the plurality of anti-resonance units jointly define a hollow fiber core, and the plurality of anti-resonance units are uniformly arranged along the outer circumference of the hollow fiber core.

The invention discloses a hollow anti-resonance optical fiber with a large mode field area and ultralow loss in a middle infrared band. The cross section structure is composed of a central pentagonal hollow core area, a peripheral glass sheet connected coaxial semicircular nested pipe cladding and an outer cladding sleeve. The hollow core is an air channel with a pentagonal outline and is used for realizing the propagation of light in a low-loss medium; the cladding is composed of five symmetrically-distributed coaxial semicircular nested tube units, each unit comprises an inner semicircular arc glass sleeve and an outer semicircular arc glass sleeve which are connected by glass sheets to form a connected structure, and an anti-resonance boundary with a periodic microstructure is formed. According to the structure, the size of an air hole, the thickness of a glass wall, the radius ratio of two layers of semi-circular arcs and geometric symmetry are accurately regulated and controlled, and light of a specific wave band is limited in the hollow core through the anti-resonance effect. The invention realizes ultralow transmission loss, large mode field area and high nonlinear threshold, and is suitable for the application fields of mid-infrared laser transmission, gas sensing, spectral analysis and the like.

An acoustic wave filter package with a surface acoustic wave resonator having a capacitor coupled in parallel with the surface acoustic wave resonator. The capacitor results in a shifted anti-resonant frequency.

This optronic sight for a motorized vehicle, such as an aircraft, marine vehicle, or land vehicle, comprises: a sighting module (13) capable of being moved around a first axis (X) and a second axis (Y) not parallel to the first axis; means (14, 15) for moving the sighting module around the first and second axes; and a feedback loop for controlling a position parameter of the sighting module based on a setpoint, comprising an adaptive feedback controller (16) capable of calculating a command for a controlled device having a critical mode that modifies the device's response. It includes means (23) capable of determining a fundamental frequency of the critical mode that varies according to an operating parameter of the controlled device, the controller (16) being calculated from the fundamental frequency determined to compensate for the anti-resonance or resonance mode. Abstract figure: Figure 5

An anti-resonant hollow core optical assembly has a central longitudinal axis extending from a first end to a second end and a diagnostic ring structure through which the central longitudinal axis extends. The diagnostic ring structure extends longitudinally from the first end to the second end, disposed azimuthally around the central longitudinal axis, comprises an outer surface at an outer radius from the central longitudinal axis and an inner surface at an inner radius from the central longitudinal axis, and has a first refractive index. A plurality of anti-resonant elements is in contact with the inner surface. The anti-resonant elements extend longitudinally from the first end to the second end and surrounds the central longitudinal axis to define an effective core region. An outer cladding surrounds the diagnostic ring structure and has a second refractive index less than the first refractive index.

Systems for gradient surface electromagnetic wave generation and related methods are described. In some implementations, a first horn antenna may be configured to disrupt momentum conservation parallel to an interface between water and another material, enabling the generation of gradient surface electromagnetic waves. A second horn antenna, positioned in proximity to the first, may be adapted to generate anti-resonances in response to the gradient surface electromagnetic waves initiated by the first horn antenna. The presence of an object, which may be composed of metal or dielectric materials, near the interface may alter the anti-resonances generated by the horn antennas. This alteration in anti-resonances may indicate the presence of the object, thereby facilitating the detection of metallic and dielectric objects in close proximity to the water surface. This system and method may enhance biosensing and bioimaging applications by supplementing traditional x-ray and ultrasound techniques with gradient surface electromagnetic wave-based detection.

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.

This invention discloses a method and apparatus for measuring the viscoelastic mechanical properties of polymers under high and low temperature environments, belonging to the field of mechanical property testing. This invention collects the admittance curves of the nth-order vibration of a resonant unit consisting of a spacer bar and a test sample, obtains the resonant frequency and anti-resonant frequency of the nth-order vibration, constructs the vibration characteristic equation and loss factor solution equation, and solves the equations to obtain the mechanical property parameters. This invention can accurately measure the viscoelastic mechanical properties of polymer materials at different temperatures. The apparatus of this invention is simple to manufacture, provides reliable measurement results, and is fast. Compared with the most commonly used methods for measuring the viscoelastic mechanical properties of polymers, whose measurement frequency range is usually below tens of Hz, this invention can obtain results at frequencies from several kHz to tens of kHz. This invention is of great significance for characterizing the mid-frequency viscoelastic mechanical properties of polymer materials and has broad application prospects.

Aspects and embodiments disclosed herein include an acoustic wave filter comprising an input and output port, a plurality of acoustic wave resonators electrically connected between the input and output port, and an impedance matching acoustic wave resonator. The impedance matching acoustic wave resonator is electrically connected on one side to a node between the plurality of acoustic wave resonators and one of the input or output port, and on a second side to one of ground or to the one of the input or output port. The impedance matching acoustic wave resonator has a resonance frequency below a low edge of a passband of the acoustic wave filter and an antiresonance frequency above a high edge of the passband of the acoustic wave filter. The impedance matching acoustic wave resonator may be a surface acoustic wave resonator having a multilayer piezoelectric substrate or a bulk acoustic wave resonator.

An acoustic wave device includes series resonators and parallel resonators formed on a main surface of a piezoelectric layer. The series resonators includes a first series resonator including first, second and third series-divided resonators and a second series resonator including fourth, fifth and sixth series-divided resonators. One of the first, second and third series-divided resonators which is disposed at a position where an electric signal is input first, has a first anti-resonance frequency. The others of the first, second and third series-divided resonators have a second anti-resonance frequency. One of the fourth, fifth and sixth series-divided resonators which is centrally disposed has the second anti-resonance frequency, the others of the fourth, fifth, and sixth series-divided resonators have the first anti-resonance frequency.

To set specifications while suppressing antiresonance in a vibration control device having a plurality of tuned mass dampers.SOLUTION: A step of assuming that the plurality of tuned mass dampers 14 are sequentially installed on the structural member 52, setting a natural frequency of the tuned mass damper 14 assumed to be installed first to a primary natural frequency of the structural member 52, and then obtaining a frequency of anti-resonance generated by one or the plurality of tuned mass dampers 14 assumed to be installed first; And a process of correcting the natural frequency of one or a plurality of tuned mass dampers 14 assumed to be previously installed to the frequency of the antiresonance obtained in the process, and setting the natural frequency of the tuned mass damper 14 assumed to be installed next.SELECTED DRAWING: Figure 6

The invention relates to a lead-free transduction element for an ultrasonic transducer and a preparation method of the lead-free transduction element, and belongs to the technical field of ultrasonic transducer equipment, the lead-free transduction element is characterized in that the lead-free transduction element is composed of a lead-free piezoelectric material and a non-piezoelectric phase material, the lead-free piezoelectric material is a quadrangular prism which is uniformly cut into a latticed crystal column array, and the non-piezoelectric phase material is a non-piezoelectric phase material. The non-piezoelectric phase material is filled among the latticed crystal column arrays; the height of the composite material composed of the lead-free piezoelectric material and the non-piezoelectric phase material is 40-60 microns, and the volume of the lead-free piezoelectric material accounts for 50-60% of that of the composite material; the volume of the non-piezoelectric phase material accounts for 40%-50% of the volume of the composite material, the side length of a crystal column is 30-40 microns, the resonant frequency and the anti-resonant frequency of the composite material are both larger than 20 MHz, and the electromechanical coupling coefficient is larger than 70%. According to the invention, the harm of a lead-based piezoelectric material in an existing ultrasonic transducer transduction element to the environment and a human body is overcome, and the provided preparation method overcomes the problems that a lead-free piezoelectric single crystal is fragile and easy to crack, and a small-size crystal column is easy to collapse when being cut.