913 results about "Side lobe" patented technology

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

A broadband signal spectrum analysis method based on spectrum leakage suppression and an improved FFT algorithm comprises the following steps: setting a broadband signal model comprising a fundamental wave frequency offset signal and a plurality of broadband oscillation signals according to broadband signal characteristics; based on a Fourier transform theory, analyzing a spectrum leakage generation mechanism of the broadband signal; a Nuttall-Kaiser combination window function is designed, and is used for suppressing the spectrum leakage of the broadband signal; the FFT algorithm is improved, and side lobe attenuation is suppressed by using the convolution window property so as to reduce the influence of spectrum leakage. According to the broadband signal spectrum analysis method based on spectrum leakage suppression and the improved FFT algorithm, spectrum leakage is effectively reduced while high frequency resolution of broadband signals is guaranteed, and meanwhile the method has the advantage of being high in measurement accuracy.

The invention discloses a vector hydrophone array orientation estimation method for performing tensor decomposition by using a propagation operator, relates to the technical field of vector hydrophone array orientation estimation, and discloses a vector hydrophone array orientation estimation method for performing tensor decomposition by using a propagation operator. The method comprises the following steps: firstly, constructing a three-dimensional array manifold tensor composed of an array direction matrix and a vector hydrophone output matrix; respectively expanding received signal tensors according to three modes, solving a propagation operator based on a column block covariance matrix, constructing a normalized signal subspace, establishing a spatial spectrum function with a noise subspace, and obtaining a pitch angle and an azimuth angle of a sound source through spectrum peak search; according to the method, high-order singular value decomposition is avoided, the operand is greatly reduced, meanwhile, high resolution and low sidelobe direction finding performance are kept, and the method is suitable for a real-time underwater acoustic direction finding system of a ship-borne platform, a buoy platform and an unmanned platform.

The invention relates to the technical field of electromagnetic simulation, in particular to a W-band antenna pointing angle simulation analysis method, which comprises the following steps: acquiring the size of a W-band antenna and the form of a radiation unit, extracting main lobe curvature and feed matching characteristics, identifying a main lobe edge interference path, and adjusting a reflection phase to form a dynamic reflectivity boundary. Dividing tetrahedron and hexahedron grids to evaluate polarization consistency, optimizing a field intensity relationship between a main lobe and a side lobe, screening an angle interval, and obtaining a directional angle correction parameter. According to the invention, the specific size and form of the antenna are acquired, the curvature distribution of the main lobe coverage area and the matching relation with the feed structure are deeply analyzed, and the reflection intensity difference between the main lobe path and the side lobe path is monitored, so that the pointing precision and the coverage efficiency of the antenna are effectively improved; according to the antenna design, the performance is ensured, the specific area can be optimized, and the predictability and the stability of the antenna performance are remarkably improved.

The invention relates to the technical field of information, and discloses a self-adaptive radio frequency energy capture method and system, and the method comprises the steps: collecting radio frequency signals in an environment, separating independent components of each frequency band signal from the radio frequency signals, determining the power density distribution and main lobe direction of each frequency band signal, and determining the deviation main direction of each frequency band signal; the antenna element spacing and the reference value of phase adjustment are determined by combining the expected gain requirement of the current environment, so that the antenna array configuration data are determined, the antenna array is controlled to scan the uncovered range of each frequency band signal, and then the full / directional capture mode is dynamically switched. The energy collection efficiency data in the current capture mode is evaluated to determine the target frequency band with sidelobe interference, the reference value of the target frequency band is adjusted, and the signal focusing effect is determined through the adjusted reference value to determine the capture priority of each frequency band signal, so that the radio frequency energy collection efficiency in the complex electromagnetic environment is effectively improved; and efficient capture and utilization of multi-band weak radio frequency signals are realized.

The invention relates to the technical field of laser radar detection, in particular to a frequency-modulated continuous wave laser radar high-precision distance measurement method, which comprises the following steps of: 1, firstly, performing noise suppression by using an improved FTRLS (Fast Transverse Recursive Least Squares) adaptive filtering algorithm aiming at a low signal-to-noise ratio signal; 2, adjusting the added limitation and filter parameters, iterating the optimal parameters, and applying the optimal effect to subsequent spectrum correction; 3, windowing the denoised signal, and carrying out FFT (Fast Fourier Transform) to obtain a frequency spectrum of the signal; and 4, smoothing the signal by using a Butterworth filter, suppressing a side lobe of a frequency spectrum due to the characteristics of the filter, and highlighting the energy of a main lobe of the signal and the position of a spectrum peak. According to the method, a redundancy feedback-dynamic restart mechanism is applied to an adaptive filtering algorithm RLS, the FTRLS algorithm which is added with a transverse filter and leads to reduction of denoising precision is greatly improved, numerical divergence of the FTRLS algorithm is inhibited by using a regularization factor, and the signal-to-noise ratio is improved.

The invention relates to an active sonar echo signal phase jump compensation method and device based on a synchronous serial number, and belongs to the technical field of underwater acoustic signal processing. The method comprises the following steps: adding a synchronous serial number into a wet end signal to form an expansion matrix; transmitting the extended signal to a signal processor and windowing the extended signal; traversing a synchronous serial number in the windowing signal, and detecting the continuity of the synchronous serial number to judge whether packet loss exists or not; if packet loss exists, positioning a packet loss position and performing zero padding operation; and finally, carrying out fast Fourier transform on the zero-filled signal to obtain a spectral analysis result. According to the method, accurate identification and phase compensation of the packet loss position are achieved through the synchronous serial number, the method is suitable for underwater acoustic single-frequency signals, and when the packet loss rate does not exceed 2.5%, spectrum sidelobes can be effectively restrained, and the peak value of the spectrum sidelobes is reduced to be within 10% of the packet loss state. The method has the advantages of being clear in principle, easy and convenient to operate and high in calculation efficiency, is suitable for real-time signal processing, and remarkably improves the reliability and efficiency of target detection.

The invention relates to the technical field of radar information, in particular to a ground clutter suppression method for a ground reconnaissance radar, which comprises the following steps of: firstly, establishing a clutter profile map by using echo data, judging information inside and outside a clutter according to the clutter profile map, and selecting different signal processing flows, namely, adopting a detection channel 1 outside the clutter, adopting a detection channel 2 and a detection channel 3 inside the clutter and adopting a detection channel 2 and a detection channel 3 outside the clutter; after the detection channel 1 passes through the MTD filter, clutter suppression processing is not carried out, and a detection result is output; the detection channel 2 is a coherent processing channel, firstly performs mean filtering processing, then performs coherent processing, performs clutter suppression processing through phasor mean filtering, and outputs a detection result; and the detection channel 3 is a zero Doppler processing channel and is used for detecting a low-speed target in a clutter area, compared with the prior art, the method can reduce Doppler sidelobes as much as possible on the premise of ensuring that the ground clutter height is suppressed, and has the minimum main lobe width and the minimum signal-to-noise ratio loss.

The invention provides a special high-throughput satellite communication terminal for electric power, and relates to the technical field of electric power communication, and the special high-throughput satellite communication terminal comprises a baseband processing module which is used for carrying out differential encryption processing on different types of electric power data; the high-throughput satellite radio frequency module is used for suppressing sidelobe interference while realizing automatic satellite beam tracking through a beam forming algorithm during satellite communication, and calculating the optimal transmitting power through a self-adaptive power regulation algorithm; the communication transmission module is used for presetting a data priority based on a priority mapping table during data transmission and preempting satellite beam resources according to the data priority; the electric power Internet of Things protocol adaptation layer is used for realizing conversion between an electric power dedicated protocol and a satellite IP protocol, differential coding compression of electric power data and interrupted transmission in a link; and the beam optimization module is used for dynamically optimizing the beam pointing angle based on the satellite orbit parameters and the terminal geographic position. According to the scheme, the coverage degree of electric power communication in remote areas can be improved, and the safety and reliability of data transmission are improved.

The invention discloses a target detection method, device and equipment based on millimeter wave radar, a storage medium and a program product. Determining a distance-Doppler map based on the echo signal received by the millimeter wave radar; determining the angle of each target based on the phase echo signal of each target; filtering the targets based on a first set threshold value and the echo intensity of each target to obtain candidate targets; determining second detection thresholds corresponding to different angles and / or different speeds; and filtering the candidate targets based on the second detection threshold, the echo intensity of each candidate target and the angle and / or speed of each candidate target to obtain a final detection target. According to the target detection method based on the millimeter wave radar provided by the embodiment of the invention, weak targets, false noise targets and sidelobe false targets caused by strong targets can be effectively filtered out, so that the accuracy of target detection is improved, and calculation resources for performing angle estimation on the targets subsequently are further saved.

The invention discloses a main lobe gain maximization method for an analog-digital hybrid array of a radar communication system. According to the method, the ratio of the maximum minimum main lobe level to the peak side lobe level is used as a target function, and under the main lobe ripple constraint, the simulation weight constant modulus constraint and the digital weight power constraint, the ADMM (Alternating Direction of Multiplexing) is used for carrying out joint design on the simulation weight and the digital weight. In the ADMM framework, a Riemann conjugate gradient method is adopted to solve a simulation weight subproblem with constant modulus constraint; and solving a digital weight by adopting a Lagrange multiplier method. A numerical result shows that the method can generate better main lobe ripples and lower peak side lobe level, and has good beam directional diagram accurate control performance.

The invention discloses a radar measurement method, device and equipment, a medium and a product, and relates to the technical field of radar signal processing. According to the method, a space angle is divided into a main lobe area and a side lobe area; determining a phase modulation strategy of twice observation of the radar; the phase modulation strategy comprises the steps that phases of a main lobe area are kept consistent in two observations, and the phase difference of a side lobe area is 180 degrees; according to a phase modulation strategy, determining a directional diagram of expected radiation of the array antenna in two times of observation, and optimizing a unit excitation weighting vector in two times of observation to obtain an optimized value of the unit excitation weighting vector; according to the optimization value, performing phase modulation on a transmitting signal of the array antenna; and coherent superposition is carried out on echo signals reflected by the target and received by the radar in two times of observation. On the premise that the array size is not changed, the anti-interference capability and the spatial resolution of the radar are remarkably improved, and the monitoring precision of the radar on parameters such as distance, speed, deformation and angle is effectively improved.

The invention relates to the field of millimeter wave radars, and discloses a 45-degree polarized array waveguide antenna for a millimeter wave radar, which comprises a metal groove layer; a slot array element layer; the slot array element layer and the metal slot layer are connected in a vertical lamination mode; the metal groove layer is provided with a plurality of radiation grooves; radiation grooves with the same number are formed in the metal groove layer at the corresponding positions of the slot array elements; the radiation slot indirectly increases the effective radiation aperture area of the antenna. The invention provides a method for solving the problems of low array pattern sidelobe, low gain and wide beam width of the N-element waveguide array antenna in a miniaturized application scene.

The invention discloses an SAR interference suppression method based on echo asynchronous pulse detection, and the method comprises the steps: constructing a local odd-even channel comparison mode or a global reference pulse comparison mode, directly carrying out the processing in a time domain of an SAR echo data matrix, determining a corresponding mode through the energy characteristics of an interference signal, and carrying out the detection of the interference signal. Constructing a channel difference mask and an outlier mask in the corresponding mode, and finally obtaining an interference mask in each mode; establishing a mask matrix based on the interference mask, and processing the amplitude matrix to obtain an amplitude matrix after interference suppression processing; and combining the phase matrix to obtain a final non-interference SAR echo data matrix. According to the method, interference artifacts brought to SAR image data by the forwarding type coherent interference can be suppressed, and the phenomenon of sidelobe deterioration of strong scattering points in the image after frequency domain notch is eliminated, so that the forwarding type coherent interference existing in the SAR echo data is effectively suppressed.

The invention discloses a dual-polarization one-dimensional scanning phased-array antenna and a weather radar system, the antenna comprises a radiation layer, a first feed layer, a first PCB layer, a second feed layer, a second PCB layer and a third feed layer which are stacked from top to bottom, and a horizontal polarization radiation unit and a vertical polarization radiation unit of the radiation layer are arranged in an orthogonally staggered manner; each first feeder is etched on the top surface of the first PCB layer and corresponds to a first metal groove formed in the bottom of the first feed layer and a second metal groove formed in the top of the second feed layer in position; and each second feed line etched on the top surface of the second PCB layer corresponds to the position of a third metal groove formed in the bottom of the second feed layer and the position of a fourth metal groove formed in the top of the third feed layer. According to the invention, high cross polarization isolation is realized, and the antenna has dual polarization beams with low side lobes and consistent beam width and pointing height in the whole working frequency band.

A high gain multiple input, multiple output antenna which has a feeding board; a ground plane; a low band patch radiator; a first printed circuit board; a second printed circuit board; and a high band dipole patch radiator. The high band dipole patch radiator is a co-located stacked array on top of the low band patch radiator. The high band dipole patch radiator and the low band patch radiator are proximity coupled with the first printed circuit board and the second printed circuit board. The low band patch radiator covers low band frequencies in the range of 2.4 GHz to 2.5 GHZ and the high band dipole patch radiator cover high band frequencies in the range of 4.9 GHZ to 7.125 GHz. The antenna assembly has a gain of above 7.5 dBi and a well-directed radiation patten with no side lobes.