19 results about "Radiation impedance" patented technology

The invention belongs to the technical field of acoustics, and particularly relates to an index type open-pore rigid plate internal vector sound field calculation method, program and equipment and a storage medium. According to a Webster equation satisfied by a simple harmonic plane sound source excitation sound pressure field, circular piston radiation acoustic impedance on an infinite baffle plate is adopted to represent radiation impedance at an opening of an exponential open pore, a sound field analytical solution of any depth in the open pore of the exponential open pore rigid plate is constructed, system calculation is carried out in combination with sound source conditions, and a sound field of any depth in the open pore of the exponential open pore rigid plate is obtained. Therefore, sound field quantities such as internal accurate sound pressure and vibration velocity of the exponential type open-pore rigid plate under the vertical incidence condition can be quickly solved, and sound field distribution conditions under different section change rules and different open-pore rigid plate sizes can be calculated. According to the method, the calculation complexity is low, the influence problem caused by sound field changes under the non-free field condition can be solved, and the calculation stability and reliability under the complex boundary condition are ensured.

The invention relates to a wave node tube and method for measuring a vibration velocity vector sensor, the wave node tube is composed of a cylindrical tube body, four standard pressure-resistant hydrophones and four high-pressure-resistant transmitting transducers, the four high-pressure-resistant transmitting transducers are of the same batch and the same model and are arranged oppositely in pairs, and the sound axes are perpendicular to each other; the standard pressure-resistant hydrophones are positioned on a sound axis and are arranged in a central symmetry manner; when in use, a measured sensor is in the center of the corrugated tube. The node tube can be used for measuring a vibration velocity vector sensor, and during measurement, the push-pull effect is generated by controlling the vibration phase of the transducer, so that the radiation impedance during vibration of the transducer is greatly reduced; and finally, by controlling the vibration amplitude of the transducer, the direction of a vibration velocity field in the tube can be controlled, and a pressure-resistant rotating device does not need to be developed.

The invention particularly relates to an active integrated antenna which comprises at least two antenna units, and each antenna unit comprises a feeder line structure used for being connected with one path of power amplifier output of a Doherty power amplifier and an antenna radiation unit connected with the feeder line structure. By adjusting the structural parameters of each antenna unit, the input impedance of each antenna unit is matched with the power amplifier output impedance of the corresponding path. The invention designs a multifunctional antenna array integrating radiation, impedance conversion and power synthesis, and the multifunctional antenna array is used for directly replacing an indispensable output matching network and a power synthesis network in a traditional Doherty power amplifier. According to the Doherty power amplifier integrated antenna, an output matching network and a power synthesis network which are necessary in a traditional Doherty power amplifier integrated antenna are eliminated, the problem that significant loss is introduced by adopting the matching network in the prior art is fundamentally avoided, and the efficiency of the Doherty power amplifier is effectively improved.

A reactive filter assembly comprising a reactive filter acoustically coupled to a transducer operable to generate an audio frequency by air nonlinearity demodulation of an ultrasonic frequency, wherein the reactive filter has a number of acoustic passes set to provide the transducer with a radiation impedance to improve the transducer efficiency.

The invention relates to an amplified reactance filter for transducer ultrasound. A reactance filter assembly includes a reactance filter acoustically coupled to a transducer operable to generate an audio frequency by air non-linear demodulation of an ultrasonic frequency, the reactance filter having a plurality of auditory conductive pathways tuned to introduce a radiation impedance to the transducer, therefore, the efficiency of the transducer is improved.

A reactive filter assembly comprising a reactive filter acoustically coupled to a transducer operable to generate an audio frequency by air non-linearity demodulation of an ultrasonic frequency, the reactive filter having a number of acoustic pathways tuned to introduce a radiation impedance to the transducer that improves transducer efficiency.

The invention discloses a finite box rectangular horn shape optimization method and system based on a hybrid model, and the method comprises the steps: carrying out the geometric discretization of a rectangular horn in the axial direction into rectangular pipeline sections which are connected end to end, and determining a to-be-optimized design variable; pre-calculating a radiation impedance matrix and a far-field directivity primary function vector under a finite box body by adopting an external radiation model; calculating an inlet impedance matrix and a speed transmission matrix of each rectangular pipeline section on the basis of a radiation impedance matrix and a current design variable by adopting a sound transmission model in the horn, obtaining a mouth output speed vector, and solving an acoustic performance index in combination with a far-field directivity primary function vector; and constructing a comprehensive objective function, and solving to obtain a finite box rectangular horn shape optimization scheme. According to the method, the edge diffraction and sound reflection effect in a limited box environment can be accurately simulated, and the radiation efficiency optimization and directivity control of the broadband of the rectangular horn are realized while the calculation cost is remarkably reduced.

The invention relates to the technical field of voice generation, in particular to a personification voice generation method and system for a carry-on AI partner, and the method comprises the following steps: collecting an external environment sound simulation signal through a carry-on equipment microphone array, obtaining an environment acoustic harmonic feature set, storing the environment acoustic harmonic feature set, and obtaining a voice simulation signal; and obtaining environment frequency spectrum characteristic data. According to the method, after a sound channel regular curled spectrum sequence is subjected to time domain smoothing to form frequency domain curled modulation data, a high-frequency-band spectrum envelope interval is extracted, amplitude gain improvement is executed according to a lip radiation impedance coefficient, then the frequency domain curled modulation data is superposed, and anthropomorphic interaction voice signals are generated. And high-frequency friction and gingival blasting details are enhanced without damaging the overall spectrum continuity, the environmental suitability, the anti-interference stability, the formant controllability and the high-frequency detail intelligibility, so that a chain gain is formed.

For a cylindrical open hole rigid plate arranged in a fluid area where a sound source is located, according to a Helmholtz equation met by a simple harmonic plane sound source excitation sound pressure field, circular piston radiation acoustic impedance on an infinite baffle plate is adopted to represent radiation impedance at an opening of a cylindrical open hole; constructing a sound field analytic solution of any depth in the open pore of the cylindrical open-pore rigid plate; the method comprises the following steps: drawing a frequency response curve of sound pressure amplitude and a frequency response curve of vibration velocity amplitude by measuring the opening cross section radius and the opening total depth of a cylindrical opening rigid plate, and taking a resonance peak and frequency values within a certain range on the two sides of the resonance peak as a resonance frequency interval; and selecting a fixed frequency in a non-resonant frequency interval range, measuring the sound pressure amplitude and the vibration velocity amplitude at any depth of the cylindrical open pore through a vector hydrophone, and correcting and restoring the real incident sound pressure amplitude and the vibration velocity amplitude of the cylindrical open pore rigid plate by using a calibration coefficient.

The invention relates to a device (10) for detecting the movement of a person (2) using microwave waves for a motor vehicle (1), said device (10) comprising a radiating impedance module (110) configured to be powered by a DC power supply (30) and including a detection antenna (112), a MOSFET-type transistor (114), and an impedance adapter (116) forming a closed-loop electrical circuit oscillating at a predetermined fixed frequency when said circuit is powered by the voltage supplied by said DC power supply (30). Figure 2

The invention discloses a structural dry-wet response conversion and underwater noise calculation method based on an acoustic impedance matrix, and the method comprises the steps: obtaining the vibration mode of an overall structure, obtaining a mode shape matrix, carrying out the forced response test of the overall structure, and obtaining the node vibration response of the overall structure. A modal participation coefficient is calculated through inversion or a regularization method, a modal with the modal participation coefficient being 0 is eliminated, response expression is updated, an immersed surface acoustic radiation impedance matrix is calculated, a modal participation coefficient vector after immersion is calculated, underwater vibration response of the structure is calculated, and underwater acoustic radiation is calculated according to immersed surface vibration response distribution and an acoustic radiation acoustic resistance matrix. According to the vibration response of the structure in the light medium and the acoustic impedance matrix of the underwater immersion surface of the structure, the prediction of the underwater vibration response and sound field distribution of the structure is realized; the method can overcome the problems of high difficulty in underwater testing, low fluid-solid coupling calculation efficiency and the like, and is a new method for conveniently and efficiently obtaining the underwater vibration sound response of the structure.

This utility model relates to the field of composite panel structure technology, specifically a sound insulation and vibration reduction partition for ship cabins containing acoustic black holes. The partition includes: an acoustic black hole thin plate layer, a damping material layer, and a honeycomb panel layer. Multiple sets of acoustic black hole structures are arranged in an array on the acoustic black hole thin plate layer, and the thickness of the acoustic black hole region satisfies a power law. The damping material layer forms an energy buffer interface, and its two sides are connected to the acoustic black hole thin plate layer and the honeycomb panel layer, respectively. The honeycomb panel layer is used to complete acoustic radiation impedance matching and suppression. This utility model constructs a complete acoustic vibration control chain of "vibration capture - energy dissipation - acoustic impedance matching" through gradient impedance design of each functional layer, improving sound insulation without increasing mass. It is particularly suitable for applications such as ship cabins that are weight-sensitive and require broadband noise reduction.

The invention discloses a method for determining guided wave frequency dispersion characteristics of a liquid-filled steel riser, which is characterized in that three-dimensional guided wave propagation is equivalent to a radial one-dimensional intrinsic problem under an axial symmetry condition, a relation between a complex wave number and frequency dispersion can be obtained only by dispersing the radial direction, and high degree of freedom of three-dimensional modeling is avoided. Internal fluid is not coupled through additional boundary terms, and is merged into the overall system by adopting a section contribution matrix, so that fluid-solid consistent assembly in the same system is realized, and error sources of coupling inconsistency are reduced. An external infinite water area does not use an absorption layer for approximation, and external water is equivalent to a wavenumber-related damping boundary by using radiation impedance meeting an infinite radiation condition; and the self-consistent complex wave number is solved through linearization and inverse iteration, so that the radiation modeling accuracy and solvability are improved.

The invention relates to the technical field of underwater acoustic sensor parameter testing, in particular to an acoustic holography acoustic array mutual radiation impedance measuring method based on an equivalent source method, which comprises the following steps of: (1) establishing an equivalent source acoustic model for a tested transmitting array object; (2) arranging an equivalent source in the target sound source, and solving the source intensity of the equivalent source by matching the measurement sound pressure of the holographic surface so as to realize space sound field transformation; and (3) reconstructing the near-field radiation sound field information of the transmitting transducer array by using an equivalent source method to realize accurate evaluation of the transducer array element mutual radiation impedance, and improving the accuracy of sound array element mutual radiation impedance characteristic measurement.

The invention belongs to the technical field of sound field calculation, and particularly relates to a sound field calculation method, program and equipment for an open cylindrical cavity embedded rigid spherical scatterer based on modal matching and spectrum expansion and a storage medium. Unified solution of intra-cavity scattering and outer domain radiation is realized through a column mode expansion and sphere-column wave function interchange relation, a mode radiation impedance matrix is constructed to eliminate an outer domain unknown spectral quantity by using a Somerfeld spectrum to naturally meet an outer radiation condition, and a numerical solution analysis framework is formed. According to the method, the calculation efficiency is remarkably improved while the geometric accuracy is guaranteed, and the method is suitable for sound field prediction and optimization design of a complex perforated structure, acoustic material and vector sensor integrated system.

The invention discloses a pipeline orifice radiation impedance testing device and method, and relates to the field of radiation impedance testing, and the device comprises an upper computer which is used for generating a control signal and an acquisition signal; the transducer is connected with the to-be-detected pipeline and the upper computer and is used for emitting sound source excitation to the interior of the to-be-detected pipeline according to the control signal; the to-be-detected pipeline is vertically placed and is filled with water; the plurality of hydrophones are distributed at different positions in the to-be-detected pipeline, are connected with the upper computer, and are used for collecting time domain sound signals at different positions in the to-be-detected pipeline in real time according to the collection signals; and the upper computer is also used for calculating the pipe orifice radiation impedance of the to-be-detected pipeline in real time by adopting a sound wave decomposition method based on the time domain sound signals at different positions in the to-be-detected pipeline. According to the invention, the pipe orifice radiation impedance of the to-be-measured pipeline can be indirectly solved through the acoustic decomposition method.

The application discloses a tunneling light-emitting device based on barrier-mode field impedance matching and a modulation method thereof, comprising a substrate, an insulating tunneling layer arranged on the substrate, and a metal nano antenna array arranged on the insulating tunneling layer, wherein the metal nano antenna array is a periodically arranged metal strip array, and the geometric parameters of the metal nano antenna array and the electrical parameters of the insulating tunneling layer are cooperatively configured, so that, under the bias voltage of the tunneling light-emitting device, the differential tunneling resistance of the insulating tunneling layer and the equivalent radiation impedance of the metal nano antenna array at the excitation wavelength realize conjugate matching or mode value matching, so as to promote the efficient transfer of the tunneling electron energy to the optical mode; the advantage is that the critical coupling of the electron tunneling rate and the optical mode radiation rate can be realized, so that the electroluminescent efficiency is significantly improved, and the energy transmission efficiency is relatively high.

The invention discloses a frequency-adjustable wide-angle scanning phased-array antenna array, and the array comprises a plurality of phased-array antenna basic units which are arranged in a 2n * 2m array structure form. Each phased-array antenna basic unit comprises a wide-angle impedance matching layer, a medium supporting layer, a frequency-adjustable radiation unit layer and a slot etching ground feed layer which are sequentially connected from the top of the antenna to the bottom of the antenna; the wide-angle impedance matching layer comprises an impedance matching layer dielectric substrate and a first metal structure etched on the upper surface of the impedance matching layer dielectric substrate; the first metal structures are arranged in a planar array form; the first metal structure is used for adjusting radiation impedance during antenna beam scanning; the frequency-adjustable radiation unit layer comprises a radiation layer dielectric substrate and a second metal structure; the second metal structure is etched on the upper surface of the radiation layer dielectric substrate, and the second metal structure is an axisymmetric etching structure. The impedance matching characteristic of the antenna array can be adjusted, the reflection loss is reduced, and wide-angle scanning is realized.

The invention relates to the technical field of underwater acoustic sensor parameter testing, in particular to a hydrophone array design method for acoustic array mutual radiation impedance near-field acoustical holography measurement, the hydrophone array design method is determined through theoretical modeling, design parameters of a hydrophone array are obtained, and the problems of the array form, the aperture, the array element spacing and the like of the hydrophone array are solved. According to the method, the problems about selection of geometric parameters such as the array frame and the like are solved, meanwhile, process design parameters of the hydrophone array are given, the needed array design parameters and process requirements are provided for research and development of the near-field measurement hydrophone array, the reliability and feasibility of research and development of the hydrophone array are improved, and meanwhile, the accuracy of near-field sound field information acquisition is also improved.