13 results about "Cylindrical wave" patented technology

The present application is suitable for the field of seismic surface wave exploration technology, and provides a passive source and active source Rayleigh wave combined exploration method and system, comprising the following steps: collecting data, the data including passive source data and active source data, uniformly using 200-300Hz sampling rate; processing data, processing the passive source data and active source data, and separately storing the active source data of each excitation point; calculating cross-correlation function and cylindrical wave dispersion. According to the present application, the passive source data and the active source data of each excitation point outside the array grouping are flexibly combined according to the array grouping, the array grouping cross-correlation function is jointly calculated, the dispersion energy graph is calculated using the cylindrical wave algorithm, the construction method is improved, the data processing is efficient, the signal-to-noise ratio of the data and the accuracy of the dispersion curve measurement are greatly improved, a feasible construction scheme and data processing algorithm are provided, and prospective research is carried out for the development of passive source and active source Rayleigh wave combined detection technology and the introduction of related regulations.

The application discloses a crimped cylindrical wave tight field device, which mainly comprises a crimped parabolic cylindrical reflector, a feed source, a quiet zone and a virtual line source. The parabolic cylindrical reflector can correct the cylindrical wave formed by the spherical wave emitted by the feed source in the quiet zone. In order to control the diffraction of the edge of the reflector, the edge of the parabolic cylindrical reflector needs to be processed. The crimped edge of the parabolic cylindrical reflector can reduce the low-frequency limit of the cylindrical wave tight field. Compared with the sawtooth cylindrical wave tight field, the electric size of the reflector working at the low-frequency limit is smaller, and the engineering realization of the large cylindrical wave tight field is more favorable.

According to the method, a multi-modal analytical model with the effects of surface waves and internal waves is established aiming at the density stratification phenomenon caused by gravity settlement and solar radiation heat effect in ocean engineering; a three-dimensional layered fluid global control equation set is constructed, a hyperbolic function combined vertical characteristic function piecewise expression is adopted to accurately characterize fluid bimodal propagation characteristics, a double-layer fluid bimodal dispersion equation is combined, a multi-body coupling matrix equation is introduced to process an inter-column wave scattering effect, and a multi-body coupling matrix equation is introduced to process the inter-column wave scattering effect. Cylindrical wave function coordinate transformation is realized by applying a Graf addition theorem, and a hydrodynamic integral expression containing additional mass and radiation damping is constructed based on a modal superposition principle. According to the method, the limitation of a traditional single-layer fluid model is broken through, the wave interference energy distribution rule under the surface wave-internal wave combined action is quantitatively analyzed, and the radiation force calculation precision and the engineering prediction applicability of the dense cylinder array in the complex marine environment are remarkably improved.

This invention discloses a waist-shaped double-slope sawtooth structure for a single parabolic cylindrical compact field, solving the edge diffraction problem of cylindrical waves incident from a linear array feed in a single parabolic cylindrical reflector compact field. The structure divides the sawtooth edges of the reflector surface into internal and external regions. The internal region employs a near-vertical base with a top triangular convergence structure to guide diffracted waves to the area above and below the quiet zone. The external region uses an inclined geometry to guide diffracted waves to the sides of the quiet zone. Each sawtooth unit consists of a five-point structure defined by a vertex, two waist points, and two base points. The position, width, and sawtooth inclination are parametrically controlled using an adjustable parameterized distribution function. This invention effectively suppresses edge diffraction in high aspect ratio compact fields, significantly improving quiet zone performance.

The application discloses a radar scattering cross section test data processing method and device, equipment and a storage medium. The method corrects the cylindrical near-field RCS test data, eliminates the deviation of the test system itself, and improves the accuracy of the test data. Further, in the environment where the size of the test target is large and the strong scattering source of non-target is introduced, the clutter filtering is used to effectively eliminate the scattering interference of the non-test target, and the real test result of the test target is obtained, and the accuracy of the test data is improved. Meanwhile, the transmission characteristics of the cylindrical wave are equivalent to the spherical wave in the horizontal component and equivalent to the plane wave in the vertical component. After the data is calibrated and the clutter is filtered, the far-field conversion is performed, and the far-field test data with high accuracy meeting the actual requirements is obtained.

This invention discloses a planar waveguide speaker with controllable directivity, comprising a speaker body. The speaker body is characterized by having a waveguide horn containing at least one sound outlet cavity. The inner surface of the sound outlet cavity includes two opposing parabolic arc surfaces and two opposing planes. By eliminating excessive transmission paths, sound pressure loss is reduced. Simultaneously, by modifying a portion of the waveguide horn's internal shape to a parabolic shape, the waveguide horn can generate cylindrical waves, improving harmful sound interference within the horn and between horns, and avoiding comb filtering in the audience's listening area.

The invention discloses an active coherent plane wave silencing device and a sound source identification method. The device comprises a sound wave guide tube designed according to the highest frequency of a target sound wave, a main sound source sound pressure signal acquisition module, a signal analysis processing control unit, an adjustable power amplifier and a secondary sound source. The sound wave guide tube converts spherical waves or cylindrical waves into plane waves through a cut-off section or an adjustable section structure; the signal analysis processing control unit identifies the characteristic parameters of the main sound source through time-frequency transformation and phase inversion calculation and generates a control signal; the secondary sound source generates interference sound waves with the same frequency and opposite phases as the main sound source, and the two form surface contact interference in the conduit to counteract target sound energy. Plane wave interference is achieved through the sound wave guide pipe, real-time sound pressure monitoring and a self-adaptive algorithm are combined, sound wave parameters are dynamically adjusted, wide-band and multi-sound-source type self-adaptive noise elimination can be achieved, and sound energy counteracting efficiency and system stability are remarkably improved.

The invention relates to the field of photonics. Existing various structures for realizing a continuous spectrum bound state still have the limitations that an infinite periodic structure cannot be realized in practice, the dielectric constant is nearly zero or the metal material loss is relatively large and the like. The invention discloses a dielectric compact structure for realizing a continuous spectrum bound state, which comprises a dielectric layer and a double-ring grating, the double-ring grating and the dielectric layer are concentric circles, the double-ring grating is of a sub-wavelength structure, and all grating units are uniformly distributed in a circumferential array manner and have the same radian. When vortex light or cylindrical wave serving as an incident source enters the continuous spectrum bound state laser, a real continuous spectrum bound state can be achieved, an infinite periodic structure is not needed, a high-loss material is not needed, the continuous spectrum bound state laser has the advantages of being compact in structure and easy to integrate, a full-dielectric scheme is adopted, and cost is reduced. The problem of large material loss caused by materials with near-zero or infinite dielectric constants is reduced, and the material can be applied to photonic devices such as lasers and sensors.

The utility model relates to the field of coaxial mid-high pitch sound boxes, in particular to a coaxial cylindrical wave mid-high pitch sound box, which ensures coaxial transmission of sound by arranging a mid-low pitch unit, a high pitch unit and a high pitch horn on the same axis, and is favorable for forming a more consistent and clearer sound field. By arranging the high-pitch fixing frame, the stability of the structure is ensured, and the high-pitch unit can be installed and adjusted in position independently of the middle-low unit. Compared with a traditional design, the mode greatly simplifies the assembly process, and meanwhile, the flexibility is also improved. By arranging the high-pitch horn, high-frequency sound waves are guided and diffused, the directivity and the coverage range of high-frequency sound are improved, and distortion is reduced. And unnecessary sound wave reflection and interference are reduced by arranging the diversion holes, so that the overall sound quality of the sound box is improved. The problems of poor independence between the alto unit and the high pitch unit and difficulty in position adjustment of the existing coaxial cylindrical wave alto-high pitch sound box are solved.

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 provides an RCS near-far field transformation method and system based on synthetic aperture imaging, and belongs to the technical field of communication radars. A strict RCS (radar cross section) near-far field transformation algorithm is established by utilizing the progressive property of cylindrical wave expansion of a Hankel function in a cylindrical coordinate system and combining near-field scattering data, so that the problem of errors caused by wavefront curvature in near-field measurement is solved, and the echo signal intensity of a to-be-measured target under a far-field condition can be accurately obtained. Based on multi-angle radar signal fusion and splicing of near-far field transformation results, a high-resolution scattering characteristic image of a to-be-measured target can be synthesized. According to the method, the distance coupling effect in near-field measurement is eliminated while the detail features of the target are reserved, so that the electromagnetic scattering behavior of the target under the far-field condition is reflected more truly.

The invention discloses a volume sound source far-field criterion confirmation method and device based on sound energy flux in a limited space, belongs to the technical field of underwater acoustic measurement, and aims to solve the problems that in the prior art, a limited space sound field is complex, a far-field criterion fails, and sound power measurement precision is insufficient. The invention provides a volume sound source far-field criterion confirmation method based on sound energy flux in a limited space. Comprising the following steps: collecting parameters of a target sound source in a limited space water area, fitting by adopting a least square method to obtain a lakebed sound attenuation coefficient, analyzing to obtain an attenuation law of a vertical space average sound pressure level, and judging whether the attenuation law accords with a cylindrical wave expansion law or not. According to the method, quantifiable judgment of the acoustic far field is realized, the precision of sound field analysis is improved, the far field boundary can be calculated and verified, and human subjective factors are reduced. The method is suitable for the field of acoustic measurement of limited water areas such as ships and ocean engineering, underwater sound test and sound source calibration and lakes and shallow seas.

The utility model provides an antenna and electronic equipment. The antenna includes a waveguide structure and a radiation structure disposed on a radiation surface side of the waveguide structure. The waveguide structure comprises a dielectric substrate which is provided with a first surface and a second surface which are oppositely arranged along the thickness direction of the dielectric substrate; the dielectric substrate comprises a first accommodating part which is at least partially penetrated along the thickness direction of the dielectric substrate, and the first accommodating part at least comprises a first opening positioned on the first surface; the reflecting layer is arranged on the second surface of the dielectric substrate; the transmission assembly is arranged in the first accommodating part; the radiation structure is located on one side of the transmission assembly deviating from the reflection structure; the transmission assembly is configured to excite the radiation structure to emit cylindrical waves.