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1110 results about "Side lobe" patented technology

In antenna engineering, side lobes or sidelobes are the lobes (local maxima) of the far field radiation pattern of an antenna or other radiation source, that are not the main lobe. The radiation pattern of most antennas shows a pattern of "lobes" at various angles, directions where the radiated signal strength reaches a maximum, separated by "nulls", angles at which the radiated signal strength falls to zero. This can be viewed as the diffraction pattern of the antenna. In a directional antenna in which the objective is to emit the radio waves in one direction, the lobe in that direction is designed to have a larger field strength than the others; this is the "main lobe". The other lobes are called "side lobes", and usually represent unwanted radiation in undesired directions. The side lobe directly behind the main lobe is called the back lobe. The longer the antenna relative to the radio wavelength, the more lobes its radiation pattern has. In transmitting antennas, excessive side lobe radiation wastes energy and may cause interference to other equipment. Another disadvantage is that confidential information may be picked up by unintended receivers. In receiving antennas, side lobes may pick up interfering signals, and increase the noise level in the receiver.

Unmanned aerial vehicle signal identification method and system in complex electromagnetic environment

The invention discloses an unmanned aerial vehicle signal identification method and system in a complex electromagnetic environment, and belongs to the field of unmanned aerial vehicles. According to the invention, the form of the liquid metal channel of the liquid metal antenna is adjusted to adapt to the target frequency band, and regional electromagnetic signals are collected in all directions. And generating spatial distribution data including the unmanned aerial vehicle and the interference direction based on the phase difference and preset features. The deformation of the liquid metal droplets is regulated and controlled through the electrowetting voltage, so that the antenna main lobe is aligned with the unmanned aerial vehicle, and the side lobe suppression area covers an interference source. Then, a target direction signal set is collected, and time domain fluctuation, frequency domain distribution and spatial domain direction multi-dimensional features are extracted; and inputting the multi-dimensional features into a joint probability model constructed by a Bayesian network, and outputting posterior probability information. Markov chain Monte Carlo self-adaptive sampling is utilized, the classification confidence coefficient is calculated through iterative convergence, the signal category is judged according to a threshold value, and the unmanned aerial vehicle signal recognition accuracy can be improved in the complex electromagnetic environment.
Owner:TIANJIN YUNXIANG UAV TECH CO LTD

Sparse array antenna optimization method based on improved zebra algorithm

The invention discloses a sparse array antenna optimization method based on an improved zebra algorithm, is used for reducing the peak side lobe level of a sparse array antenna, and belongs to the technical field of radio frequency phased array antennas. The implementation process of the method comprises the following steps: firstly, adding a probability estimation model on the basis of an original zebra optimization algorithm, and converting a real number variable into a binary code; secondly, an adaptive T distribution disturbance strategy and a dynamic selection strategy are introduced, the global search capability of the algorithm is enhanced, the algorithm is prevented from falling into local optimum, and the convergence speed is effectively improved; and finally, an optimal solution is obtained through iterative optimization for a certain number of times. In order to verify the performance of the method, three groups of simulation experiments are carried out, and the result shows that compared with other optimization algorithms, the method can obtain a lower array antenna peak sidelobe level within shorter optimization time, so that the performance of the antenna is improved.
Owner:BEIJING UNIV OF POSTS & TELECOMM +1

Comprehensive method for thin cloth rectangular plane broadband array antenna

The invention relates to a thin cloth rectangular plane broadband array antenna synthesis method, and belongs to the technical field of array antenna optimization. The method comprises the following steps: firstly, establishing a mathematical model of a rectangular plane broadband array antenna, initializing parameters of the broadband array antenna, and performing sparse processing on a full array by using a Kaiser weighting function; secondly, initializing a sparse array position population by adopting Tent chaotic mapping, calculating an array element to generate a population fitness function value, and recording an optimal individual; thirdly, adopting an improved grey wolf optimization algorithm to carry out sparse optimization on the sparse array, calculating an updated array element fitness value, extracting an optimal fitness value, recording a corresponding array element position, and outputting an optimal array element position arraying scheme; and finally, obtaining a frequency invariance directional diagram with a smaller side lobe based on the SRV constraint of infinite norm. According to the invention, the number of antenna array elements can be effectively reduced, the frequency-invariant wave beam of the minimum side lobe is realized, and the cost of an antenna system is reduced while the performance of the broadband array antenna is ensured.
Owner:CHONGQING UNIV OF POSTS & TELECOMM

Large-scale phased array multi-channel partition beam control method and device based on FPGA and storage medium

The invention discloses a large-scale phased array multi-channel partition beam control method and device based on an FPGA and a storage medium. The method comprises the steps that a control instruction of an antenna control unit is acquired; analyzing the control instruction which is verified to be correct, judging an instruction type according to an analysis result, when the instruction type is a beam switching instruction, determining a beam control parameter in the instruction, and calculating a base code of the phased-array antenna according to the beam control parameter; the array elements of the phased-array antenna are divided into a plurality of areas, according to the base codes and the position coordinates of the array elements, the wave control codes of the array elements are calculated in parallel by adopting a multi-channel partitioning method, and the wave control codes are normalized and then written into a beam forming chip in parallel; and after the operation is completed, a corresponding response instruction is sent to the antenna control unit. The method has the advantages of being high in beam switching speed, small in resource consumption and good in universality, an array can form a sparse array in the mode of sending a control instruction, and therefore side lobes are restrained, and power consumption is reduced.
Owner:WUHAN ZHONGYUAN COMM CO LTD

Communication sensing integrated beamforming method and system for suppressing distance-angle sidelobe

The invention provides a communication perception integrated beamforming method and system for suppressing distance-angle side lobes, and the method comprises the steps: enabling a base station to communicate with a plurality of users under a digital beamforming ISAC architecture, and carrying out the detection of an air target in a self-transmitting and self-receiving mode at the same time; determining a sensing channel model and a communication channel model to obtain a communication receiving signal at each user position and a sensing receiving signal scattered back to the base station from the target; calculating to obtain the SINR of each user; a distance-angle-Doppler three-dimensional perception fuzzy function based on a digital beam forming ISAC architecture is obtained; extracting an expression of an integral sidelobe of a distance-angle dimension; according to the communication index, the sensing index and the integral sidelobe value in the preset distance-angle sidelobe area, a beam forming matrix of the ISAC system is designed in a joint optimization mode; auxiliary variables are introduced to convert the problem of optimizing the beam forming matrix into the problem of optimizing a covariance matrix of the beam forming matrix, and a feasible solution of the joint design problem is obtained.
Owner:SHANGHAI JIAOTONG UNIV +2

Satellite beam scanning scheduling method and device and storage medium

The invention discloses a satellite beam scanning scheduling method and device and a storage medium. The method belongs to the field of satellite communication, and comprises the following steps: acquiring parameter characteristics of coverage areas of multiple beams of a satellite; inputting the parameter features into a pre-trained neural network model, and determining sub-bands adapted to the plurality of beams through the neural network model; a chromosome vector is initialized, an initial population is constructed, and the chromosome vector is used for indicating the beam position scanned by each beam of the satellite in each beam hopping time slot of the beam hopping period; constructing a fitness function; performing iterative optimization on the initial population according to a genetic algorithm, and determining an optimal chromosome vector; and according to the optimal chromosome vector, determining the beam position scanned by each beam in each beam hopping time slot of the beam hopping period. Therefore, coverage overlapping and sidelobe leakage interference of same-frequency beams are avoided to the maximum extent from the scanning time sequence dimension, and dual targets of sub-band adaptation and interference suppression are synchronously achieved.
Owner:GALAXY AEROSPACE (BEIJING) NETWORK TECH CO LTD

Intelligent metasurface-assisted phased array transmitting beam directional diagram accurate control method

The invention discloses an intelligent metasurface-assisted phased array transmitting beam directional diagram accurate control method. An intelligent metasurface RIS is introduced into a phased array transmitting system, and an additional signal propagation path is added for transmitting beam forming by utilizing the characteristic that the RIS can freely regulate and control a reflected signal, so that an additional system degree of freedom is obtained. Specifically, a difference value between a minimum peak side lobe power and a minimum main lobe power of a transmitted beam is taken as a target function, and under phase-only transmission weight constraint, main lobe ripple constraint and RIS constant modulus constraint, an alternating direction penalty method is utilized to carry out joint design on a phase-only transmission weight and RIS phase shift. In the iterative solution of the alternating direction penalty method, the subproblem with the constant modulus constraint is solved by adopting a backtracking projection gradient descent method. The method provided by the invention can generate smaller main lobe ripples and lower peak side lobe level, and has better accurate control performance of a beam directional diagram.
Owner:NANJING UNIV OF SCI & TECH

Sparse combination array measurement system and method for underwater target radiation noise measurement, program and storage medium

The invention belongs to the technical field of underwater target radiation noise measurement, and particularly relates to a sparse combination array measurement system and method for underwater target radiation noise measurement, a program and a storage medium. A sparse combined array formed by a sound pressure spiral double-cone volume array with a sparse structure and a sound pressure vector nested vertical linear array is designed, a combined array frequency-division testing scheme of a high-frequency volume array and a low-frequency vertical linear array is adopted, a combined measurement method of a sound pressure hydrophone and a vector hydrophone is utilized, a measurement frequency band is extended, and the measurement precision is improved. And effective measurement of the full-band radiation noise of the underwater target is realized. Through a sparse array arrangement structure and an improved constant-beam-width beam forming method, a two-dimensional steady constant-beam-width beam is obtained while the number of array elements is reduced and the array complexity is reduced, and an appropriate main lobe width and a lower side lobe level can be adjusted according to a measured target and a measurement distance. According to the method, the array element redundancy of the measurement array is reduced, and the method can be flexibly applied to various application scenes of underwater radiation noise measurement.
Owner:HARBIN ENG UNIV

Multi-target anti-interference detection system based on holographic staring radar

The invention discloses a multi-target anti-interference detection system based on a holographic staring radar, relates to the technical field of holographic staring radars, and constructs a technical architecture consisting of an array calibration module, a beam forming and optimizing module, a self-adaptive filtering module and a self-adaptive control module. Interference between beams is effectively suppressed by adopting a minimum sidelobe beam forming algorithm, dynamic suppression of near-angle strong interference is realized by combining spatial domain-time domain combined filtering, and beam parameters are adaptively optimized by utilizing fusion analysis and a feedback mechanism, so that the multi-target detection precision and the anti-interference capability of the system in a complex urban environment are remarkably improved, and the system has a wide application prospect. The stability and the practicability are relatively high.
Owner:HEBEI XINMATRONIC INFORMATION TECHNOLOGY CO LTD

Millimeter wave circularly polarized ridge gap waveguide antenna

The invention discloses a millimeter wave circular polarization ridge gap waveguide antenna. The waveguide antenna comprises a feed waveguide layer, a waveguide gap layer, a grating lobe suppressor, a polarization converter and a radiation cavity layer which are sequentially stacked from bottom to top. The waveguide antenna adopts an interdigital ridge structure, so that electromagnetic wave leakage radiation can be effectively inhibited, the stability of the working mode of the antenna unit is ensured, and the isolation of the antenna in a large-scale array is enhanced; the feed waveguide layer and the waveguide slot layer are spliced to form the interdigital ridge structure, the production and assembly process is simple, the welding process is omitted, and the production cost is reduced; left-hand circular polarization or right-hand circular polarization can be switched on the polarization converter by changing the orientation of the cross-type gap. By feeding from the two ends of the feed waveguide layer, a dual-circular-polarization working mode can also be realized; by adjusting the size of each slot on the waveguide slot layer, the flexibility of grating lobe suppression can be improved, and the side lobe level of the antenna can be reduced. The invention relates to the technical field of antennas.
Owner:SOUTH CHINA UNIV OF TECH

High-precision spectral interference signal demodulation method for micro distance measurement

The invention discloses a high-precision spectral interference signal demodulation method for micro distance measurement. The method comprises the steps of S1, interference spectrum shaping; measuring an interference spectrum and a reference spectrum; selecting a six-item combined cosine window as a primary function of an interference signal to obtain a shaped interference spectrum; s2, performing non-uniform Fourier transform to obtain a frequency spectrum of the target signal; s3, on the basis of a multi-spectral-line interpolation algorithm, interpolation is carried out on the window function to solve a fitting function, and a center frequency k is obtained; and S4, outputting a result. And solving and outputting an optical path difference d. According to the method, a six-item cosine combination window is selected as a primary function of an interference signal, and the problem that the accuracy of signal extraction is influenced by mutual superposition of side lobes and even main lobes of a direct current item and a solved frequency item is solved; an interference spectrum is processed by using a fast non-uniform Fourier transform algorithm, accuracy can still be kept under the conditions that the distance to be measured is increased and sampling is gradually sparse, and the problem of resampling deviation caused by a traditional interpolation method can be solved.
Owner:HEFEI UNIV OF TECH

Multi-strategy joint improved sparse area array optimization method and system

The invention discloses a multi-strategy joint improved sparse area array optimization method and system, and the method comprises the steps: calculating the peak side lobe level of each initial array element distribution, and obtaining the current lowest peak side lobe level and the optimal array element distribution corresponding to the lowest peak side lobe level, updating the positions of the array elements according to an ascending stage, a descending stage and a landing stage in the improved dandelion optimization algorithm; starting a Cauchy spiral inverse cumulative distribution variation strategy to vary the positions of the array elements, calculating the target lowest peak side lobe level of the updated array element distribution, and if the value of the target lowest peak side lobe level is greater than the value of the lowest peak side lobe level, replacing the updated array element distribution; and updating the global optimal array element distribution position and the corresponding lowest peak sidelobe level. The efficiency of the algorithm in the aspects of global search and local development is improved, the algorithm is prevented from being caught in local optimum too early, and therefore the solving precision and the convergence speed of the algorithm are improved.
Owner:JIANGXI UNIVERSITY OF FINANCE AND ECONOMICS +1

Waveform optimization method and system for underwater acoustic detection and communication integrated system

The invention relates to the field of underwater acoustic communication and detection, in particular to a waveform optimization method and system for an underwater acoustic detection and communication integrated system. According to the method, a constant modulus phase is taken as a constraint, a reserved subcarrier phase is taken as an optimization variable, and a multi-objective function for joint optimization of a peak-to-average power ratio and a non-periodic autocorrelation integral sidelobe ratio is constructed; a population is initialized, an objective function is evaluated, and a parent population is obtained through non-dominated sorting and crowding distance calculation; generating filial generations through selection, crossover and variation, combining the filial generations with the parent generations, and updating sorting and crowding distance to maintain population diversity; introducing a local gradient descent refinement mechanism, carrying out gradient iteration adjustment on an optimized individual under a constant modulus phase condition, and adaptively adjusting a crossover probability, a mutation probability and a phase variation scale according to a diversity evaluation result; and outputting a Pareto optimal solution set after the maximum number of iterations is reached, and obtaining an optimized sounding and communication integrated orthogonal frequency division multiplexing signal, so that the underwater communication and detection comprehensive performance can be effectively improved.
Owner:INST OF ACOUSTICS CHINESE ACAD OF SCI

Audio data processing method and device and electronic equipment

The invention discloses an audio data processing method and device and electronic equipment, and relates to the field of audio processing. The method comprises the following steps: acquiring original multichannel audio data through a microphone array; generating a main beam output signal pointing to the target sound source direction and at least one sidelobe suppression output signal; extracting voiceprint feature vectors; comparing the voiceprint feature vector of the current frame with the center vector of the existing voiceprint class cluster to obtain a voiceprint clustering result; if it is determined that the first voiceprint class cluster and the second voiceprint class cluster exist, extracting a first audio frame belonging to the first voiceprint class cluster and a second audio frame belonging to the second voiceprint class cluster, and performing audio reconstruction to obtain a first voice stream and a second voice stream; and carrying out residual noise elimination on the sidelobe suppression output signal to obtain a first isolated audio stream and a second isolated audio stream. By implementing the technical scheme provided by the invention, the audio processing quality is improved.
Owner:SHENZHEN SOUNDFIT TECH CO LTD

Beam weight generation method, device and equipment

The embodiment of the invention provides a beam weight generation method, device and equipment, and relates to the technical field of communication, and the method comprises the steps: respectively setting signal snapshots and array manifold vectors of an expected angle and an unexpected angle of a to-be-generated beam; wherein the expected angle is an angle corresponding to a main lobe of a to-be-generated beam, and the unexpected angle comprises an angle corresponding to a side lobe of the to-be-generated beam; generating a cost function according to the set signal snapshot and the array manifold vector; the variable of the cost function is the weight of a to-be-generated beam, and the dependent variable is the sum of a first preset parameter and a second preset parameter; and performing iterative operation on the cost function on the basis of a preset local particle swarm optimization algorithm based on a von Noiemann topological structure so as to obtain a target weight of the to-be-generated beam. According to the embodiment of the invention, the technical problem that the beam directivity and the main lobe power are difficult to consider in the existing weight generation mode of the multi-peak beam can be solved.
Owner:RUIJIE NETWORKS CO LTD

Non-cooperative target side lobe sensing method and system, medium and equipment

The invention discloses a non-cooperative target sidelobe sensing method and system, a medium and equipment, and belongs to the technical field of spectrum sensing. The method comprises the following steps: acquiring a to-be-sensed sidelobe signal emitted by a non-cooperative target; establishing a cooperative sensing problem of to-be-sensed sidelobe signals under different signal-to-noise ratios; inputting the to-be-sensed sidelobe signal into a pre-constructed sensing network model, and outputting a sidelobe sensing result of the non-cooperative target; wherein the processing step of the sensing network model comprises the following steps: according to the cooperative sensing problem, judging a sensing result of a to-be-sensed sidelobe signal at a sensing node; and deciding a sidelobe sensing result of the non-cooperative target according to a sensing result of the to-be-sensed sidelobe signal at the sensing node. According to the method, the cooperative sensing problem of the to-be-sensed sidelobe signals under different signal-to-noise ratios is established, and the sensing result is judged and decided through the cooperative sensing problem, so that the accuracy of detecting the non-cooperative sidelobe signals is greatly improved.
Owner:ARMY ENG UNIV OF PLA

Passive antenna array beam forming test method and system

The invention provides a passive antenna array beam forming test method and system, and relates to the technical field of beam forming test. According to the method, channel baseline parameters are established in a silencing environment, frequency hopping and channel switching are combined to realize multi-frequency-point synchronous sampling, a reference source and self-polling data are utilized to calculate a mutual coupling correction matrix and a feeder line consistency factor, and weight projection and equivalent aperture field generation are completed without changing physical wiring conditions; further extracting a main lobe direction, a beam width, a side lobe level and a scanning consistency index through far field transformation, and unwrapping and smoothing a frequency-point-crossing phase result; and meanwhile, generating a unique traceability identifier, establishing full-link association between a test condition and a result, and outputting a criterion conclusion. According to the method, the accuracy, efficiency and traceability of passive array beam testing are improved.
Owner:ZUNYI NORMAL COLLEGE

Unit rotation and mutual coupling considered sparse linear array beam forming method and system

The invention relates to the technical field of array antennas, in particular to a sparse linear array beam forming method and system with unit rotation and mutual coupling considered. Array elements are obtained, Euler angle derivation is carried out on rotation of the array elements around the z axis, and a radiation electric field after rotation is obtained; setting a beam forming target according to the electric field of the radiation field; according to a beam forming target, optimizing the position, the rotation angle and the excitation phase of an array element by adopting a random optimization algorithm, and generating an initial beam scheme; an active directional diagram is extracted from the initial beam scheme according to full-wave simulation, the active directional diagram is combined with a CAL-SAPSO algorithm to optimize the array element position, the rotation angle and the excitation phase, and a final array element directional diagram is generated; according to the invention, by introducing array element rotation and considering a mutual coupling effect, efficient beamforming of the sparse wiring array is realized, the radiation characteristic of the antenna array can be adjusted more finely, the peak side lobe level and the cross polarization level are effectively reduced, and the overall performance of the system is improved.
Owner:XIDIAN UNIV

Dual polarization radar

Various embodiments relate to a radar system, including: a transmitter; a transmit antenna connected to the transmitter, wherein the transmit antenna is a circular polarized antenna; a receiver; a receive antenna connected to the receiver, wherein the receive antenna is a dual polarization antenna having a main lobe and ambiguity sidelobes; wherein the radar system is configured to: transmit a first and second radar signal with first and second circular polarizations in first and second modes; receive reflected first and second radar signals; process the received first and second radar signals to detect a target and to produce first and second mode target powers; comparing the first mode target power to the second mode target power to determine which lobe of the antenna in which the target is located.
Owner:NXP BV

Portable satellite communication station signal optimization method and system

The invention discloses a portable satellite communication station signal optimization method and system, relates to the field of wireless communication, and is used for synchronously realizing dynamic adaptive management of multiple scattering paths. The method comprises the following steps: generating an earth surface image through multi-modal detection data, and carrying out layered calibration on scattering intensity; identifying a high-reflection sub-region according to the surface image and the layered calibration information thereof, and performing unified management on high-reflection and weak echo paths; based on the gain, interference and angle information of the multiple scattering paths, performing sub-array division on the antenna array according to priorities; phase stepping correction is carried out on the antenna units of the sub-arrays, and emission excitation is combined in adjacent path coverage areas; through a dynamic power scheduling and beam forming algorithm, the direction gain of each sub-array is optimized and sidelobe leakage is controlled. According to the invention, synchronous management of high reflection and weak echo paths can be realized, and the dynamic adaptability to scattering scenes is improved.
Owner:四川领航未来通信技术有限公司

SAR (Synthetic Aperture Radar) active interference identification method and system storage device under low interference-to-signal ratio condition and electronic equipment

The invention discloses an SAR (Synthetic Aperture Radar) active interference identification method under a low interference-to-signal ratio condition, a system storage device and electronic equipment. The method comprises the following steps: carrying out normalization processing on a time domain image of interference, and weakening a sidelobe influence through power law transformation after carrying out normalization processing on a time-frequency domain image; taking the preprocessed time-domain image and the time-frequency-domain image as dual-channel input of the network, and extracting multi-scale features by using a diversified branch block and a channel attention mechanism; fusing the extracted time domain features and the extracted time-frequency domain features through a weighted fusion strategy, carrying out dynamic weight distribution on the features of the time domain and the time-frequency domain, and introducing variance parameters of signals and interference to carry out feature optimization under a low interference-to-signal ratio; and inputting the fused feature sequence into a Transform, calculating the attention weight of any position through a Query-Key-Value matrix, capturing a long-distance dependency relationship, and enhancing global feature representation. According to the method, the SAR active interference pattern under the low interference-to-signal ratio can be identified with high precision, and powerful support is provided for a subsequent anti-interference strategy.
Owner:HENAN UNIVERSITY

Parallel simulation method for guided wave focusing imaging of composite structure piezoelectric array

The invention discloses a parallel simulation method for guided wave focusing imaging of a piezoelectric array of a composite structure, belongs to the technical field of nondestructive testing, and aims at solving the problems that the sound field control precision of a current multi-array-element piezoelectric structure in a composite material plate is insufficient, and a traditional finite element method is large in calculation time consumption, low in convergence speed and high in reliability in the guided wave propagation simulation process. In order to solve the problem that effective convergence cannot be realized under the excitation condition of a high-frequency multi-channel array and even under the excitation condition of a high-frequency multi-channel array, the invention provides an efficient guided wave focusing simulation strategy combining spectral element high-order precision and GPU parallel computing, and the method comprises the following steps: establishing a system control equation considering a piezoelectric-structure coupling effect on the basis of a delay superposition principle; energy focusing and sidelobe suppression of a guided wave signal in a specific direction are realized by adjusting spatial arrangement and excitation time sequence of a piezoelectric array sensor, Gauss-Labatto-Legendre integral nodes are introduced to construct a high-order spectral element unit, unit-level parallel solution is realized under a CUDA architecture, and dynamic simulation capability and overall calculation efficiency of focusing field distribution are remarkably improved.
Owner:DONGGUAN UNIV OF TECH

Acoustic imaging system of concentric circle nested microphone array

PendingCN120559582APosition fixationSound sourcesNested arrays
The invention relates to the technical field of acoustic imaging, and discloses an acoustic imaging system of a concentric-circle nested microphone array, which comprises a central microphone and the concentric-circle nested microphone array. The concentric nested microphone arrays are concentrically arranged by taking the central microphone as the center, a plurality of microphones are distributed on each layer of circular microphone array according to a nested array rule, and the distance between each layer of adjacent microphone arrays is d. By adopting a unique circular nested microphone array structure, the position information of a sound source can be accurately captured through the cooperative work of multiple layers of microphone arrays. A plurality of microphones are distributed in each layer of microphone array in a circular nested array, a multi-dimensional sound acquisition network is formed by combining a central microphone, and meanwhile, the signal processing module gradually extracts and reconstructs sound source information in a sound field by utilizing a CLEAN-SC algorithm and through iterative decomposition and removal of strongest components in sound source signals, so that a sidelobe interference image is effectively inhibited, and the sound quality is improved. Therefore, a high-resolution sound power distribution diagram is obtained, and acoustic imaging is realized.
Owner:NORTH CHINA ELECTRIC POWER UNIV

Microwave array accurate positioning method based on radio frequency signals

The invention discloses a microwave array accurate positioning method based on a radio frequency signal. The method comprises the following steps: S1, receiving navigation satellite signals from a BDS system, a GPS system and a GLONASS system; s2, the received GNSS signals are preprocessed; s4, performing enhancement processing on the weak signal; s5, performing fusion processing on the main lobe signal, the side lobe signal, the strong signal and the weak signal by using a multi-signal fusion algorithm; s6, a microwave array antenna is installed on the spacecraft; s7, fusing a microwave array positioning result with a positioning result of the multi-constellation combined navigation system by using a position calculation and correction algorithm; s8, transmitting a positioning result to a ground control center through a data transmission module; and S9, according to the signal strength and the positioning precision monitored in real time, weak signals are effectively enhanced by adopting adaptive beam forming and spatial filtering technologies, noise interference is suppressed, and the system can stably work in a complex environment.
Owner:成都中微达信科技有限公司

Time domain broadband adaptive beam forming method and system based on Chebyshev weighting

The invention relates to a time domain broadband adaptive beam forming method and system based on Chebyshev weighting, and belongs to the field of array signal processing. Aiming at the technical problems of poor real-time performance and high sidelobe of the existing broadband beam forming, the method comprises the following steps of: dividing a received broadband signal into a plurality of sub-bands, obtaining an optimal weight vector for each sub-band by adopting a minimum linear constraint iterative algorithm after down-conversion, constructing an expected response of an FIR filter according to each weight, obtaining a filter coefficient through L2 norm convex optimization, and finally obtaining a high sidelobe beam according to the expected response of the FIR filter. And performing time domain weighting on each array element signal by using a filter bank, and outputting a directional beam. According to the method, the calculated amount is low, a main lobe and interference null can be formed in real time in a broadband, and a certain side lobe height is kept.
Owner:SOUTHEAST UNIV +1

DOA estimation and error correction method and device based on joint sparse recovery

The invention provides a DOA estimation and error correction method and device based on joint sparse recovery, and the method comprises the steps: receiving a target signal through a linear array, building an array signal model fusing a phase error, and constructing an optimization model based on multiple measurement vectors; and compensating the phase error in each step of iteration by using an iterative optimization solution algorithm to enable the DOA to gradually approach a true value, thereby obtaining estimation results of the spatial spectrum and the phase error. The method provided by the invention has the advantages that random phase errors caused by array element position errors, system frequency errors, sound wave propagation errors and the like in DOA estimation are corrected. Under the condition that phase errors exist, a signal model and an optimization problem are constructed, and the phase errors and a DOA estimation value are solved through an iterative algorithm, so that a high-precision and low-sidelobe DOA estimation result is obtained. The method is suitable for DOA estimation under the conditions of small snapshots, strong noise and random phase errors.
Owner:INST OF ACOUSTICS CHINESE ACAD OF SCI

Ultra-wideband array antenna based on common-caliber layout

The invention relates to the technical field of array antennas, and discloses a common-caliber layout-based ultra-wideband array antenna, which comprises a low-frequency unit and a high-frequency unit which are arranged based on a common caliber, and is characterized in that the working frequency of the low-frequency unit covers an fmin-f0 frequency band, and the working frequency of the high-frequency unit covers an f0-fmax frequency band. The low-frequency unit is a broadband dual-polarized antenna, a uniform tight coupling array distributed at equal intervals is formed by adopting a tight coupling principle, and the unit interval is calculated based on a grating lobe suppression condition at the frequency f0. The high-frequency unit is a miniaturized broadband dual-polarized antenna and adopts a sparse array form; the initial unit spacing and the unit number of the sparse array are calculated based on the grating lobe suppression condition at the highest frequency f2 of the f1-f2 frequency band with the side lobe requirement between the f0-fmax frequency bands. The ultra-wideband array antenna gives consideration to full-band array performance, can provide sufficient space for active circuit arrangement, and effectively reduces power consumption and cost.
Owner:10TH RES INST OF CETC

Ground clutter mitigation with half-duplex circularly polarized AESA radar

An aerial monopulse active electronically scanned array (AESA) radar system includes a phased array of independently controllable radio frequency (RF) channels, a beamforming module, and a transmit / receive module. The beamforming module is configured to cause the phased array to produce a radiation pattern with intercardinal sidelobes oriented along a shortest axis to ground, during flight. The transmit / receive module is configured to half-duplex operation of the phased array by switching between left-hand circular polarization and right-hand circular polarization.
Owner:ROCKWELL COLLINS INC

High-precision measuring method and device for harmonic waves / inter-harmonic waves of power broadband signals

The invention discloses a power broadband signal harmonic / inter-harmonic high-precision measurement method and device. The method comprises the following steps: constructing a constrained N-element linear equation set for solution according to a windowed signal spectrum asymptotic expression, designing a normalized N-order W-window function with the performance of analyzing a digital frequency interpolation coefficient and a minimum sidelobe, performing double weighting on a broadband signal by using different-order W-windows, performing spectrum density detection based on an amplitude spectrum, and determining the spectrum density of the broadband signal according to the detected spectrum density. And a W window frequency interpolation factor and a correction formula are adaptively switched according to a detection spectral line difference value to measure a broadband signal. The method does not need to fit a frequency interpolation coefficient, is small in calculation amount, is high in robustness, is easy to achieve, and effectively achieves the real-time high-precision measurement of harmonic / inter-harmonic parameters in a broadband range.
Owner:NARI NANJING CONTROL SYSTEM CO LTD

Array error robust narrowest beam synthesis method based on sparse optimization

The invention provides an array error robust narrowest beam synthesis method based on sparse optimization. According to the method, for the problem that a main lobe area of an array antenna cannot be accurately determined under the low side lobe constraint, slack variables are introduced, the high-gain spot beam optimization problem is converted into the main lobe width minimization problem, robustness control over array amplitude-phase errors is introduced into the constraint, and the beam forming performance under the condition that array errors exist is remarkably improved. The method comprises the following calculation steps: 1, constructing a comprehensive convex constraint condition of a directional diagram according to beam pointing and an upper bound of an array amplitude-phase error; 2, constructing a cost function based on a logarithm minimization problem of an e index sum, and constructing a directional diagram comprehensive convex optimization problem; and 3, solving an optimization problem by using a convex optimization solving tool. According to the method, while the width of the main lobe is minimized, accurate control over the characteristics of the main lobe and the side lobe of the directional diagram is achieved under the condition that the amplitude-phase error boundary is given.
Owner:NANJING UNIV OF SCI & TECH