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296 results about "Spherical wave" patented technology

Such waves are generated by a point source, and they make possible sharp signals whose form is altered only by a decrease in amplitude as r increases (see an illustration of a spherical wave on the top right). Such waves exist only in cases of space with odd dimensions.

Method for estimating channel parameters of reconfigurable intelligent surface channels based on spherical wave assumption

A method for estimating channel parameters of a reconfigurable intelligent surface based on a spherical wave assumption includes the following steps. In Step 1, a signal transmission model of a RIS-assisted near-field communication is constructed based on the spherical wave assumption; in Step 2, channel measurement data in different RIS transmission modes are obtained; in Step 3, a delay, an angle of arrival, an angle of departure, a Doppler shift and a polarization matrix of multipath in channels are estimated based on a space-alternating generalized expectation maximization algorithm, and angle parameters, distance parameters and coupling polarization matrices of the multipath at a RIS end are estimated based on a maximum likelihood principle; and in Step 4, the estimated parameters are updated and iterated subsequently. The method can estimate all important channel parameters in the RIS-assisted near-field communication scenario more accurately.
Owner:SOUTHEAST UNIV +1

Multi-target CRB minimization method for near-field flux-sensing integration based on rate splitting

The invention discloses a multi-target CRB minimization method based on near-field flux and inductance integration of rate splitting, and relates to the technical field of wireless communication and novel multiple access. The method comprises the following four steps: S1, establishing a near-field communication channel and a near-field sensing channel according to a spherical wave propagation model; s2, the base station encodes information required by a communication user into public and private information streams by using a rate splitting multiple access technology and sends the public and private information streams to the user side; s3, according to the array response vector of the near-field sensing channel, deriving CRBs for simultaneously estimating angles and distances of a plurality of sensing targets; and S4, establishing an optimization problem by satisfying the communication rate requirement and minimizing the CRB of multiple targets, and jointly optimizing the hybrid beam forming matrix and the common rate allocation variable by using a penalty dual decomposition and block coordinate descent method. The method can achieve the simultaneous estimation of the distances and angles of a plurality of sensing targets, and effectively reduces the estimation error.
Owner:XUZHOU MEDICAL UNIVERSITY

Flying-over beam pattern scanning hologram microscope device using scan mirror and translation stage

A flying-over beam pattern scanning hologram microscope device includes: a scan beam generation unit which converts a first beam and a second beam to a first spherical wave and a second spherical wave, and then allows the first and second spherical waves to interfere with each other to form a scan beam; a scanning unit, which comprises a scan mirror for controlling the scan beam in the horizontal direction, and a translation stage for moving an object in the vertical direction at the rear end of the projection unit; the projection unit projecting the scan beam onto an object plane; and a light collection unit for detecting a beam that has passed through the objective lens again after fluorescing or being reflected from an object.
Owner:CUBIXEL CO LTD

Method for measuring acoustic impedance on surface of material in situ by embedded microphone array

The invention provides a method for measuring acoustic impedance of a material surface in situ by using an embedded microphone array. The method comprises the following steps: arranging a rectangular microphone array on the surface of a material to be measured; the microphones are divided into two groups; setting a sound wave incidence angle, arranging a sound source in a half space on one side of the surface of the material based on the sound wave incidence angle, and collecting sound pressure through two groups of microphones; respectively describing a sound source radiation sound field and a boundary reflection sound field by using two groups of spherical wave primary functions; on the basis of the two groups of spherical wave primary functions, a mass point vibration velocity component in a unit normal vector direction is obtained, and the mass point normal vibration velocity at the first group of microphones is reconstructed by using sound pressure distribution collected by the two groups of microphones; and based on the material surface sound pressure and the mass point normal vibration velocity collected by the first group of microphones, calculating the acoustic impedance rate at the first group of microphones, and averaging to obtain the surface acoustic impedance rate of the to-be-measured material. Influence of sound scattering of components on a sound field is avoided, and sound pressure measurement precision is improved.
Owner:湖北东湖实验室

Inclined wave surface sub-aperture stitching interference detection method based on spatial light modulator

The invention discloses an inclined wave surface sub-aperture stitching interference detection method based on a spatial light modulator, and relates to the field of optical detection. Light emitted by the laser is collimated and expanded and then enters the polarizing beam splitter; the reflected light is used as a reference light beam, and the transmitted light is used as a test light beam; a test light beam enters the spatial light modulator, is subjected to phase modulation by the spatial light modulator, passes through the lens and then forms standard spherical waves with different inclination angles, and zero detection is carried out on sub-apertures divided in different regions. The spatial light modulator is used as an ideal point source array generator to be matched with the imaging lens, so that required ideal inclined spherical waves can be generated according to different parameters of a measured piece, and compared with a traditional point source generator, the device has high universality. And for a large-aperture complex curved surface, sub-aperture splicing can be realized without moving an interference device, and errors caused by mechanical movement are reduced.
Owner:NANJING UNIV OF SCI & TECH

Target detection and channel estimation method for near-field sensing integrated system

The invention discloses a target detection and channel estimation method for a near-field sensing integrated system. The method comprises the following steps: a base station sends a downlink pilot signal to a sensing target and receives a corresponding echo signal; then, a user sends an uplink pilot signal to estimate a user channel; according to the characteristics of a near-field channel, a sensing and communication signal model based on a spherical wavefront hypothesis is established; according to the characteristics of a near-field channel, firstly, a near-field channel model is approximated by adopting Fresnel approximation, then a low-overhead dictionary based on near-field spherical wave approximation is provided, and on the basis, an improved orthogonal matching pursuit algorithm is designed for near-field communication perception to estimate parameters of a perception target and a communication channel. According to the invention, parameters of a near-field sensing target and a channel can be estimated with low overhead, and the estimation precision of the parameters in a near-field scene is improved.
Owner:ZHEJIANG UNIV +1

A geometric random and beam-domain wireless channel modeling method for very large-scale MIMO

The present invention discloses a method for modeling ultra-large-scale MIMO geometric random and beam-domain wireless channels, and the specific steps include: 1) setting simulation parameters, network layout, etc., generating initial large-scale parameters, and generating initial clusters based on model initialization parameters; 2) updating large-scale and small-scale parameters; 3) generating geometric random channel model channel coefficients, steering matrices, and beam-domain channel matrices; 4) analyzing channel characteristics, and verifying the accuracy of the model by comparing with measured data. The wireless channel modeling method established by the present invention supports spherical waves and spatial non-stationary characteristics, and can realize the conversion from geometric random to beam-domain channel models under near-field conditions. The model accuracy is verified by the consistency of simulation and measurement results of space-time-frequency correlation functions and channel capacity. The present invention has guiding significance for the design and performance evaluation of ultra-large-scale MIMO communication systems.
Owner:SOUTHEAST UNIV

Physical property inversion-oriented spherical wave oscillation-slow nuclear high-order decoupling method and device

The invention relates to a spherical wave oscillation-slow nuclear high-order decoupling method and device for physical property inversion, and belongs to the field of geophysical detection and acoustic detection. The method comprises the following steps: obtaining and inputting observation data, and initializing seabed elastic parameters; determining an integral interval according to the observation data, decomposing the integral interval into a plurality of sub-intervals, and setting a decoupling order; calculating an oscillation nuclear local integral matrix of each order corresponding to the observation data incident angle; calculating the angle deviation guiding quantity of each order of the slowly-varying kernel; calculating a reflection coefficient vector of each order of spherical wave; calculating a spherical wave reflection coefficient of high-order decoupling; and solving a subsequent inversion problem by using the obtained high-order decoupled spherical wave reflection coefficient. According to the method, the calculation efficiency of the seabed spherical wave reflection coefficient in the inversion process is effectively improved; the decoupling order is improved, the calculation precision is improved, or the number of the subintervals can be reduced by improving the decoupling order under the condition that the calculation precision is certain.
Owner:FIRST INSTITUTE OF OCEANOGRAPHY MNR

Seabed elastic parameter inversion method, system and device under seismic spherical reflection wave oscillation-slow change nuclear decoupling framework

The invention relates to a seabed elastic parameter inversion method, system and device under an earthquake spherical reflection wave oscillation-gradual change nuclear decoupling framework, and belongs to the field of geophysical detection and acoustic detection. The method comprises the following steps: (1) inputting observation data and initializing seabed elastic parameters; (2) determining an integral interval and decomposing the integral interval into a plurality of sub-intervals; (3) calculating an oscillation nuclear local integral matrix corresponding to the incident angle of the observation data; (4) calculating a slowly-varying kernel local mean vector; (5) calculating a spherical wave reflection coefficient of oscillation-gradual change kernel decoupling; and (6) constructing a target function by using the decoupled spherical wave reflection coefficient, and solving the target function. In the objective function solving process, only the steps (4) and (5) need to be repeatedly executed after the seabed elastic parameters are updated, the oscillation nuclear local integral matrix in the step (3) does not need to be repeatedly calculated, redundant calculation about oscillation nuclear integration is avoided, and the calculation efficiency is improved.
Owner:FIRST INSTITUTE OF OCEANOGRAPHY MNR

System for measuring performance of equipment under test, and method therefor

Disclosed are a system and a method for a high-speed performance measurement. The system includes: a fixing part; a positioner for controlling the rotation of the equipment by controlling the fixing part; a measurement probe; a curved reflective plate for reflecting, in the direction of the measurement probe, an electromagnetic wave radiated by the equipment and transforming the spherical wave of the measurement probe into a plane wave at the position where the equipment is provided; an arc structure including an arc arranged to be adjacent to the fixing part; a probe set including near-filed probes arranged to be spaced predetermined intervals apart from each other on the inner side of the arc; and a control unit, which receives, through a signal analyzer, signal data corresponding to an input signal from some of near-filed probes and the measurement probe.
Owner:REPUBLIC OF KOREADIRECTOR GENERAL NAT RADIO RES AGENCY

Near-field electromagnetic source positioning method based on array signal processing

The invention provides a near-field electromagnetic source positioning method based on array signal processing, and relates to the technical field of electromagnetic signal detection and positioning, and the method comprises the steps: constructing an array receiving signal model based on the wave-front characteristics of an electromagnetic wave spherical surface, and employing a steering vector for the construction; a sensor array is used for collecting near-field radiation source signals, and amplitude calibration processing is carried out on the near-field radiation source signals to form an array data set. According to the near-field electromagnetic source positioning method based on array signal processing, high-precision three-dimensional positioning of a near-field electromagnetic source is realized by combining amplitude calibration, characteristic decomposition and joint optimization processing through an array receiving signal model based on electromagnetic wave spherical wavefront characteristics. According to the near-field electromagnetic source positioning method based on array signal processing, a multi-dimensional optimization strategy is introduced in the signal subspace extraction and parameter estimation process, the estimation precision of the distance, the pitch angle and the azimuth angle is improved, and the positioning stability and robustness in a complex electromagnetic environment are improved.
Owner:HUNAN INST OF METROLOGY & TEST

High-gain low-RCS metasurface antenna with wave beam deflection function

The invention provides a high-gain low-RCS (radar cross section) metasurface antenna with a wave beam deflection function, which belongs to the technical field of electromagnetic metamaterials and comprises an upper-layer metasurface and a lower-layer metasurface, and multifunctional regulation and control on an electromagnetic wave radiation scattering mode are realized by adopting the upper-layer metasurface and the lower-layer metasurface which are different in size. Wherein the upper-layer metasurface is a PCM-FSS scattering-transmitting integrated metasurface, and the lower-layer metasurface is a phase gradient metasurface. When the high-gain low-RCS metasurface antenna works in a radiation mode, the upper-layer metasurface emits spherical electromagnetic waves downwards, and when the spherical waves reach the lower-layer metasurface, the spherical waves are reflected into high-gain directional wave beams with the deflection angle being 34 degrees through phase compensation and penetrate through the upper surface to be radiated to a free space; when working in a scattering mode, the upper and lower layers of metasurfaces can deflect reflected waves of external electromagnetic waves to a non-threat angular domain direction. In the frequency band of 8-18 GHz, the RCS reduction amplitude reaches 10 dB or above, and in-band and out-of-band large-amplitude RCS reduction is achieved while high-gain radiation is kept.
Owner:SHANXI UNIV

Super-large-scale MIMO uplink signal detection method suitable for near-field spherical waves

The invention relates to the field of wireless communication, in particular to an ultra-large-scale MIMO uplink signal detection method suitable for near-field spherical waves, and in a near-field spherical wave model system, aiming at the problem of relatively large user interference caused by a communication scene with dense users, uplink signal detection specifically comprises the following steps: dividing a receiving antenna array into C non-intersecting sub-arrays, constructing a factor graph model by taking each array as a factor node and taking a sending signal of each user as a variable node; according to the factor graph model, approximate posterior distribution of a signal sent by a certain user on a subarray is obtained through calculation; and iteratively updating the received signal and the channel matrix of each sub-array based on a sorting interference elimination algorithm to complete signal detection. According to the method, better performance can be obtained in a multi-user near-field scene, and better detection performance can still be kept in a scene in which multiple users reach the center of the array at the same angle but at different distances.
Owner:CHONGQING UNIV OF POSTS & TELECOMM

Micro-distance sensing method and system of MEMS ultrasonic sensor array

The invention relates to the technical field of sensor sensing, and discloses a microspur sensing method and system for an MEMS ultrasonic sensor array, and the method comprises the steps: carrying out the phase calibration of the MEMS ultrasonic sensor array, and obtaining a phase calibration parameter; performing near-field spherical wave phase compensation on the phase calibration parameter based on the macro target distance and the incident angle to obtain a near-field compensation parameter; controlling the MEMS ultrasonic sensor array to execute beam forming of wide beam scanning and narrow beam focusing according to the near-field compensation parameter to obtain a macro focusing sound field; transmitting ultrasonic waves to a rear vehicle target through the micro-distance focusing sound field and receiving a reflection signal, and performing vehicle feature recognition on the reflection signal to obtain a vehicle recognition result; and positioning calculation of the target angle and distance is carried out based on the vehicle identification result to obtain rear vehicle positioning data, and the angle resolution and the distance measurement precision in a microspur range are improved.
Owner:ULTRONIX PRODS

Diversion tunnel inner surface acoustic echo point extraction method

The invention relates to the technical field of safety monitoring and health management in the service period of a diversion tunnel in water conservancy and hydropower engineering, in particular to a diversion tunnel inner surface acoustic echo point extraction method which comprises the following steps: (1) an omnidirectional sonar actively emits sound waves to irradiate the inner surface of the tunnel, and meanwhile, periodic sampling is performed to form a series of discrete echo data points; (2) filtering direct waves, multipath echoes and noise data points in the discrete echo data points, and reserving actual echo data points on the inner surface of the tunnel; (3) one frame of data in the actual echo data points is used as a processing unit, and the intensity value change rate R between the adjacent data points is calculated one by one; (4) distance information and intensity information represented by acoustic echo points on the inner surface of the diversion tunnel should be optimal values, the acoustic echo points should be distributed at positions with large reflection echo intensity values and dense reflection echo intensity values in a short-distance spherical wave propagation mode, and the distance and intensity information is considered as a whole; the next data point with the maximum intensity value change rate between the adjacent data points is taken as an acoustic echo point P of the current frame data; (5) acoustic echo point extraction is carried out on the discrete echo data points of the next frame according to the steps (3) and (4) until acoustic echo points of all data frames are extracted and stored; according to the method, the problem of multiple data points formed by echo periodic sampling can be effectively solved, tunnel inner surface acoustic echo points giving consideration to strength information and position information are extracted, and reliable data support is provided for reconstruction and disease detection and recognition of the diversion tunnel inner surface.
Owner:HUAIYIN TEACHERS COLLEGE

Multi-beam switching antenna applied to wind finding radar and working method of multi-beam switching antenna

The invention relates to a multi-beam switching antenna applied to a wind finding radar and a working method of the multi-beam switching antenna. The antenna comprises a connecting device, a feed device and a lens device, the connecting device is a subminiature push-in connector, the input end of the connecting device is connected with the wind finding radar, and the output end of the connecting device is connected with the feed device; the feed device comprises a GCPW-SIW conversion structure and a feed source antenna. Wherein the feed source antennas are sixteen antipodal Vivaldi antennas and are used for radiating spherical waves to the lens device; the lens device is a metasurface lens, and the feed device and the lens device are arranged in an offset-focus mode. Therefore, phase compensation is carried out on spherical waves radiated by a feed device located at the focus of the lens, and the spherical waves are converted into plane waves of the emergent surface of the lens. Compared with the prior art, the method has the advantages that the actual application requirement of a wind measurement radar system is met, and accurate wind field measurement and data acquisition are achieved.
Owner:SHANGHAI UNIV

Spherical near-field antenna measurement method and system

The invention discloses a spherical near-field antenna measurement method and system, and the method comprises the steps: generating a sampling point coordinate sequence on a measurement spherical surface based on a preset algorithm, and enabling the sampling point coordinate sequence to form a continuous spiral track from a first pole to a second pole; controlling the measuring probe to move at a constant speed along the continuous spiral track, and synchronously acquiring near-field complex electric field data of the to-be-measured antenna when the measuring probe moves to each sampling point to form a complex electric field data vector; constructing a linear equation of spherical wave expansion based on the complex electric field data vector, the sampling point coordinates and the measured spherical radius, and solving the linear equation by adopting a regularization method to obtain a spherical wave coefficient vector; and calculating a far-field pattern of the to-be-tested antenna based on the spherical wave coefficient vector. According to the invention, the technical problems of high sampling redundancy, discontinuous mechanical scanning path, dependence on interpolation and low precision in the existing antenna measurement technology are solved.
Owner:FOSHAN LANPUDA TECH CO LTD

Flying-over beam pattern scanning hologram microscope device using spatial modulation scanner and translation stage

A flying-over beam pattern scanning hologram microscope device includes: a scan beam generation unit which converts of a first beam and a second beam to a first spherical wave; a scanning unit, which includes a spatial modulation scanner for controlling the scan beam in the horizontal direction, and a translation stage for moving an object in the vertical direction at the rear end of the projection unit; the projection unit projecting the scan beam onto an object plane; and a light collection unit which detects a beam that has passed through the objective lens again after being reflected or fluoresced from the object.
Owner:CUBIXEL CO LTD

Ultrathin dual-polarized lens antenna based on double-layer Huygens metasurface

The invention discloses an ultrathin dual-polarized lens antenna based on a double-layer Huygens metasurface, and relates to the technical field of plane transmission array antennas. The ultrathin dual-polarized lens antenna based on the double-layer Huygens metasurface is provided with a horn antenna feed source module and a double-layer Huygens metasurface module. The double-layer Huygens metasurface module is composed of a medium supporting layer in the middle and metal patch layers of which the top layer and the bottom layer are identical in structure. The unit grids of the double-layer Huygens metasurface module are arranged according to hyperbolic phase distribution to form a super-lens function, and quasi-spherical waves emitted by the horn antenna feed source module are converted into plane waves emitted in a single direction, so that the directivity and radiation gain of electromagnetic waves are improved. The antenna has the advantages of dual polarization response, ultra-thin thickness smaller than one tenth of wavelength, easy integration, high radiation gain and high aperture efficiency, and can be widely applied to the fields of millimeter wave communication systems, wireless power transmission and the like.
Owner:XIAMEN UNIV

Imaging method, imaging device, head-mounted display and storage medium

The invention discloses an imaging method, an imaging device, a head-mounted display and a storage medium. The method comprises the steps that phase modulation is carried out on spherical waves emitted by point light sources through a mask to change propagation parameters of the spherical waves, the propagation parameters comprise at least one of the phase and the amplitude, the parameters of the spherical waves with different depths are different after the spherical waves are modulated by the mask, and a shot scene comprises a plurality of point light sources; generating a grayscale image based on the spherical wave after the propagation parameter is changed; and based on a preset high-dimensional reconstruction model, performing high-dimensional reconstruction on the grayscale image to generate a high-dimensional image containing depth information. Depth information of spherical waves is captured through a mask, the size, the weight and the cost of hardware are reduced, a grayscale image including the depth information is obtained, high-dimensional reconstruction is performed on the grayscale image, the depth information of each pixel is decoded, the scene content of a shot scene is displayed, meanwhile, the depth information of the shot scene and an object in the shot scene is accurately reflected, and the image quality is improved. And detection of multi-dimensional information of a scene is realized.
Owner:YONGJIANG LAB

Seismic energy estimation method based on generalized spherical wave propagation

A seismic energy estimation method based on generalized spherical wave propagation, relating to the field of earthquake engineering. The method comprises: determining initial seismic total energy and seismic power on the basis of seismic source characteristics and a seismic magnitude; determining a generalized spherical wave equation, and calculating an average energy flow density of propagated waves on the basis of the wave equation of spherical waves; using an earth surface spherical crown, which is projected on the zone of a seismic source surface, as a main impact zone of seismic spherical waves on an earth surface, the main impact zone being equivalent to a square and performing grid division, and calculating the hypocentral distance between the center of each grid and the center of a seismic source so as to form a hypocentral distance matrix; and expressing the generalized spherical wave energy flow density of each grid as the sum of the energy flow density of longitudinal waves and the energy flow density of transverse waves, performing grid subdivision, estimating the average amplitude of each subdivided grid mass unit within a seismic action period, and evaluating the seismic action energy of a site. The present invention estimates the action of seismic energy on the earth surface by defining the generalized spherical wave propagation of seismic source energy, thereby more accurately evaluating the distribution condition of seismic energy on the earth surface.
Owner:3RD CONSTRUCTION (SHENZHEN) CO LTD OF CHINA CONSTRUCTION 5TH ENGINEERING BUREAU

Multi-input multi-output channel model construction method and device, network equipment and medium

The invention provides a multiple-input-multiple-output channel model construction method and device, network equipment and a medium, and relates to the technical field of wireless communication. The method comprises: according to at least one obtained model parameter, determining a spatial non-stationary matrix and a near-field spherical wave matrix corresponding to a multiple-input-multiple-output (MIMO) channel, the at least one model parameter being obtained based on a three-dimensional (3D) MIMO channel model; elements in the spatial non-stationary matrix are used for describing the visibility of clusters in the MIMO channel to antenna array elements, and the near-field spherical wave matrix is used for describing the influence of spherical wave propagation on signal amplitude and phase; and according to the spatial non-stationary matrix and the near-field spherical wave matrix, a target MIMO channel model is constructed, and the target MIMO channel model is used for simulating a channel coefficient of the MIMO channel. According to the scheme of the invention, the problem that the existing MIMO channel model is not suitable for the simulation test of a large-scale MIMO channel is solved.
Owner:BEIJING UNIV OF POSTS & TELECOMM

Illumination system based on plane waves and exposure equipment

The invention relates to the technical field of holographic lithography systems, and discloses a plane wave-based illumination system and exposure equipment, and the plane wave-based illumination system comprises a first lens group and a second lens group which are sequentially arranged along an optical axis direction; the first lens group is used for expanding the laser output by the light source; the second lens group is used for collimating the expanded laser and outputting plane wave laser to the direction of the holographic mask; the distance between the first lens group and the second lens group is the sum of the effective focal length of the first lens group and the effective focal length of the second lens group. The light beam is expanded by the first lens group, then the light beam is collimated by the second lens group, and the wave aberration of the illumination system can be reduced by adopting the form of the lens group, so that the photoetching resolution is improved; and compared with a traditional projection photoetching illumination system and a holographic mask illumination system based on spherical waves, the number of used lenses can be reduced, and the manufacturing cost is reduced.
Owner:HYPER-OPTICS (BEIJING) TECH LTD

Aspheric surface shape detection system and method based on polarized light wavefront modulation

The invention relates to an aspheric surface shape detection system and method based on polarized light wavefront modulation. The system comprises a laser interferometer, a first aperture diaphragm, a polarization splitting prism, a 1 / 4 wave plate and a to-be-detected aspheric surface which are coaxially arranged, and a half wave plate, a second aperture diaphragm and a spatial light modulator which are coaxially arranged, before the laser interferometer emits spherical waves, the polarization state is changed into a horizontal line polarization state after passing through the first aperture diaphragm and the polarization splitting prism, the polarization state is changed into a circular polarization state after passing through the 1 / 4 wave plate, the spherical waves are reflected on the aspheric surface to be measured, the reflected light is changed into a vertical line polarization state after passing through the 1 / 4 wave plate, and the reflected light is reflected on a polarization splitting film of the polarization splitting prism. And the light passes through the second aperture diaphragm and is modulated by the spatial light modulator, the modulated light returns along the original light path to form interference fringes, and the interference fringes are analyzed by the laser interferometer to obtain measurement data. Compared with the prior art, the method has the advantages of no need of additional compensation elements, easiness in adjustment and measurement, high universality and the like.
Owner:SHANGHAI INSTITUTE OF TECHNICAL PHYSICS CHINESE ACADEMY OF SCIENCES

Three-Dimensional Superdirective Antenna and Optimization Method

A three-dimensional (3D) superdirective antenna and optimization method is disclosed herein. The antenna includes: a multilayer substrate, a plurality of radiating elements, and an excitation module. The several radiating elements are mounted on the multilayer substrate to form a 3D radiating element array. The excitation module includes an excitation circuit and a beamforming module that measures radiation fields generated by the array both with and without coupling effects. An embodiment may also generate a coupling matrix based on spherical wave coefficient expansion of the measured radiation fields and determine a superdirective excitation vector based on the coupling matrix. An embodiment may also excite the radiating elements using the excitation vector to generate a superdirective beam. Compared with existing antenna technology, embodiments disclosed herein may dynamically realize a superdirective beam in an alignment direction and demonstrate excellent performance in both directivity and realizable gain.
Owner:TECH INNOVATION INST SOLE PROPRIETORSHIP LLC +1

Coherence tomography wavefront measuring device and method based on optical fiber interconnection and point diffraction

The invention belongs to the field of optical measurement and detection, and particularly relates to a coherence tomography wavefront measurement device and method based on optical fiber interconnection and point diffraction, the measurement device separates a fundamental mode and a high-order mode of test light through a few-mode optical fiber, the fundamental mode generates a reference spherical wave through point diffraction to serve as reference light, and the high-order mode serves as the test light; after the test light and the reference light are subjected to optical fiber coupling interference, an interference pattern is obtained by a detector, and wavefront error measurement and optimization are realized through wavefront calculation and correction. The method has high precision and high stability, and can realize rapid closed-loop feedback correction.
Owner:CHANGCHUN INST OF OPTICS FINE MECHANICS & PHYSICS CHINESE ACAD OF SCI

A millimeter-wave communication codebook design method and related components

This invention provides a near-field millimeter-wave codebook generation method and related components. The near-field millimeter-wave codebook generation method is applied to a near-field hierarchical communication beamcodebook system. The method includes: obtaining the level number of the codebook at the current level in the near-field hierarchical communication beamcodebook system; determining the codebook level of the current level according to the relationship between the level number and a preset level, wherein the codebook level includes an upper-level codebook and a lower-level codebook; and obtaining a near-field millimeter-wave communication codebook based on the codebook level of the current level. The near-field millimeter-wave codebook generation method provided by this invention considers the characteristics of the spherical wavefront in the near-field region, avoids performance degradation, and achieves coverage of the entire Fresnel region. It designs a lower-level codebook covering polar coordinates and an upper-level codebook designed to reduce beam search overhead.
Owner:TSINGHUA UNIVERSITY

A near-field strong interference suppression method based on spherical wave deconvolution beamforming positioning

The application discloses a near-field strong interference suppression method based on spherical wave deconvolution beam forming positioning, which comprises the following steps: performing fine grid division on a near-field scanning area of a linear array; performing spherical wave focusing beam forming on the near-field scanning area and two-dimensional deconvolution beam forming about distance-angle under the condition of unknown sound source position; calculating the distribution entropy characteristics of the deconvolution beam forming result in the angle dimension, and using a preset threshold to correlate the interference positioning of a target; constructing an array flow pattern matrix A of each near-field target l and generating a covariance matrix A; calculating the orthogonal complement space projection matrix of the covariance matrix A, and applying the orthogonal complement space projection matrix to the array element domain covariance matrix C to perform near-field interference suppression; using a far-field plane wave model to perform deconvolution beam forming calculation on the covariance matrix for suppressing near-field interference, so as to obtain passive detection results of the near-field strong interference suppression. The application can realize near-field interference positioning and interference suppression under the condition that the interference position is unknown.
Owner:THE 715TH RES INST OF CHINA SHIPBUILDING IND CORP

Fleeting beam pattern scanning hologram microscope apparatus utilizing a scanning mirror and a transfer stage

The present invention relates to a fly-by light beam pattern scanning hologram microscope apparatus using a scanning mirror and a transfer stage. The present invention provides a fly-by light beam pattern scanning hologram microscope apparatus, comprising: a scanning light beam generating unit modulating a phase of a first light beam separated from a light source to convert the first light beam into a first spherical wave through a first lens, converting a second light beam into a second spherical wave through a second lens, and then making the first spherical wave interfere with the second spherical wave to form a scanning light beam; a scanning unit including a scanning mirror for controlling the scanning light beam in a horizontal direction to transmit it to a projection unit and a transfer stage for moving an object in a vertical direction at a rear end of the projection unit; a projection unit including a plurality of lens systems and an objective lens and projecting the scanning light beam transmitted from the scanning unit on an object plane; and a light collecting unit for detecting a light beam that has passed through the objective lens again after fluorescing or reflecting from the object, wherein the scanning light beam projected on the object plane has different patterns according to a conical angle condition and a focal point position of each of the first spherical wave and the second spherical wave formed on the scanning mirror.
Owner:CUBEPIXEL LTD

Light interference and diffraction experiment device

ActiveCN223217928UEducational modelsLaser transmitterInterference phenomenon
The utility model discloses a light interference and diffraction experiment device, which comprises a laser transmitter and a first experiment part, the first experiment part comprises an interference instrument and a diffraction instrument; the interference device is of a thin sheet structure with uniform thickness, can be arranged on a propagation path of a laser beam, and divides the laser beam incident to the interference device into two emergent beams, so that the interference phenomenon of light is observed; the diffraction instrument can be arranged on the propagation path of the laser beam, one half of the laser beam entering the diffraction instrument is shielded, and the other half of the laser beam forms a spherical wave at the edge of the diffraction instrument, so that the diffraction phenomenon of light is observed. According to the utility model, the first experiment part can reproduce a Young's double-slit interference experiment and a Fraunhofer single-slit diffraction experiment only by using a flat sheet under the condition that double slits and single slits are not needed, and can intuitively show physical mechanisms such as wave splitting surfaces and wave surface limitation; and experiments of circular hole diffraction, cross diffraction, Poisson bright spots and the like can be demonstrated.
Owner:SICHUAN NORMAL UNIV +1