HomeAbout journalEditorial boardPeer EvaluationInstruction to authorsAdvertisementSubscriptionEthics StatementContact usChinese
Information

ParentUnit China Electronics Technology Group Corporation

Unit Nanjing Research Institute of Electronics Technology

PublishHouse Modern Radar Editorial Office

PrintingPlant

DomesticPublishHouse

PostID

ExternalPublishHouse

ServiceTel 025-51821080/81/83/85/86/88

Email modernradar@126.com

Address Editorial department of Modern Radar, No.8 Guorui Road, Yuhuatai District, Nanjing 210039, P. R. China

  • Current Issue
  • Online First
  • Archive
  • Most Downloaded
    Select AllDeselectExport
    Display Method:
    Exper Forum
    Development of Airborne AESA Fire Control Radar
    Ben De
    2024,46(2):1-15, DOI:
    [Abstract] (339) [HTML] (0) [PDF 26.40 M] (100)
    Abstract:
    Airborne fire control radar is the core sensor of the fighter. Airborne fire control radar has experienced the development history of rangefinder, pulsed Doppler radar and phased array radar. The current state of the airborne fire control radar is summarized in this paper. Considering the demand changes of future fighters and the technology evolution, the development trends of airborne fire control radar is explored. With the emerging technologies such as multi-sensor integration, distributed detection, smart skin, radar stealth and monolithic integration, this paper provides reference for the subsequent airborne fire control radar design and research.
    Development status and prospect of semantic segmentation of multi-source remote sensing images
    HE You, LIU Yu, TAN Daning, ZHANG Yiming, ZHANG Caisheng, SUN Shun, DING Ziran, JIANG Qiaowen
    2024,46(2):16-24, DOI:
    [Abstract] (282) [HTML] (0) [PDF 8.88 M] (25)
    Abstract:
    Semantic information extraction of remote sensing images is becoming one of the key technologies in urban planning and utilization, land cover survey, disaster change detection and maritime situational awareness. Starting from the intelligent processing requirements of remote sensing images developed from single-source to multi-source, the development status of semantic segmentation of remote sensing images in the era of big data and in the context of deep learning is summarized and analyzed firstly in this paper,including single-source image semantic segmentation, multi-source remote sensing image fusion semantic segmentation and multi-source(homogeneous/ heterogeneous)remote sensing image change detection. Then, on the basis of expounding the main methods, the key technologies of semantic segmentation of multi-source remote sensing images are refined and summarized, including fast semantic segmentation of single-source remote sensing images, accurate registration and fusion of multi-source remote sensing images assisted by semantic information, and intelligent extraction of semantic information based on multi-source remote sensing images. Finally, aiming at the on-orbit processing requirements of multi-source remote sensing images, the technical challenges faced by intelligent integrated information extraction of high-resolution multi-source remote sensing images are summarized,and the future development trend is prospected.
    Microwave Photonic Signal Synchronization and Its Application in Distributed Coherent Radar
    PAN Shilong, ZHANG Zhijian, WANG Xiangchuan, LIU Xi, YANG Sihao, CAO Xinrong, WANG Lihan, CHENG Qiang, MA Cong, DING Zeyong, GUO Deming, WU Guangxin
    2024,46(2):25-34, DOI:
    [Abstract] (290) [HTML] (0) [PDF 12.60 M] (46)
    Abstract:
    Based on high-performance signal synchronization among multiple radars, distributed coherent radar can realize signallevel coherent fusion, significantly enhancing radar detection, tracking, and anti-jamming capabilities, which represents one of the important development directions in the field of radar. As the frequency range and instantaneous bandwidth continue to expand,and platform forms diversify, distributed coherent radar technology demands increasingly precise signal synchronization in terms of time, space, frequency, and phase. This poses significant challenges to traditional electrical signal synchronization technologies.The performance requirements of signal synchronization technologies and reviews of the research progresses are presented in this paper.Then, the basic principles and representative achievements of microwave photonic synchronization technologies which address synchronization challenges in time, space, frequency, and phase domains are summarized. Finally, a proof-of-concept system for microwave photonic distributed coherent detection is constructed, verifying the feasibility of distributed coherent detection. Microwave photonic signal synchronization provides an important technological pathway for advancing the frontier development and engineering applications of distributed coherent radar.
    Deceptive Interference Suppression Technology Based on Spatiotemporal Filtering
    XING Mengdao, HU Shenghui, LIN Hao
    2024,46(2):35-41, DOI:
    [Abstract] (278) [HTML] (0) [PDF 12.23 M] (46)
    Abstract:
    Deceptive interference has strong directionality in space. Their decomposition (projection) can be realized effectively in the Doppler domain by utilizing the angle-doppler relation of SAR signals. Taking advantage of this, a joint spatial-temporal adaptive filter based on multiple Doppler constraints is proposed in this paper, which can realize effective suppression of deceptive interference signals in combination with multi-channel SAR system. The space-time spectrum of the effective signal and DFI is firstly analyzed and estimated. Then the squint MSAR data are processed. The main lobe DFI is removed by using the subspace projection matrix and the suppression of the side lobe DFI and the reconstruction of the signal spectrum are realized by using the multidoppler direction linearly-constrained minimum variance (MDD-LCMV) beamformer. In this paper, the effectiveness of the proposed algorithm is verified by point simulation experiments.
    Group Orthogonal Waveform Sets Design for MIMO Radar
    SUN Jinping, LIU Tianqu, QIAO Yaqiong, HU Weidong
    2024,46(2):42-47, DOI:
    [Abstract] (283) [HTML] (0) [PDF 7.75 M] (16)
    Abstract:
    In modern electronic countermeasures, digital radio frequency memory (DRFM) devices can quickly intercept airborne pulse Doppler radar signals and achieve diverse jamming to interfere with multiple-input multiple-output (MIMO) radar. MIMO radar can combat the DRFM-based jamming using multiple group orthogonal waveform sets. At the same time, to maximize the waveform diversity gain of MIMO radar, the waveforms transmitted within each pulse also need to be orthogonal. To balance the intra and inter-group orthogonality, a group orthogonal waveform sets optimization model is formulated. The objective function is the weighted sum of the evaluation metrics of intra-and inter-group correlation functions. To solve this optimization problem, a group orthogonal waveform sets design method is proposed. The proposed method simplifies the origin optimization problem into a p-norm optimization problem. To minimize the objective function, an iterative solving formula is derived based on the MM algorithm. The simulation results show that the proposed method can flexibly balance the interference suppression and range compression performances of MIMO radar by adjusting the weighting factor.
    A study on passive situational awareness system for maritime targets
    ZHANG Caisheng, LIU Yu, SONG Jie, SUN Shun, WANG Cong, HE You
    2024,46(2):48-55, DOI:
    [Abstract] (265) [HTML] (0) [PDF 18.59 M] (36)
    Abstract:
    Accurate situational awareness of maritime targets in 24/7 is crucial for safeguarding national maritime rights and ensuring maritime safety. In response to the limitations of existing passive detection technologies such as wireless detection and photoelectric detection in detecting target types and multi-target detection capabilities, as well as the anti-interference and concealment capabilities of active radar, experimental research on passive perception technology for sea targets based on pulse radar signals was conducted, targeting various ships on the sea surface. The basic principle of passive situation perception system for targets detection was provided. The measurement of direct wave pulse signal parameters, analysis of antenna scanning characteristics and data pre-processing, pulse accumulation and moving target indication processing, constant false-alarm rate detection and display correction were completed based on field measurement data. The trial results were verified and analyzed using ship automatic identification system information, which verified the feasibility and effectiveness of maritime targets detection by passive situation perception technology based on non-cooperative pulse radar signals.
    A Study on Key Technologies of Airborne Fire Control Software Radar
    JIANG Ming, TANG Jun, TAN Xianglin, YANG Yanlin
    2024,46(2):56-61, DOI:
    [Abstract] (278) [HTML] (0) [PDF 10.10 M] (51)
    Abstract:
    The inherent characteristics, development trends, and the urgent need for transitioning from “digitization” to “softwareization” of airborne fire control radar are analyzed in this article. First,the software radar technology system is outlined from the perspectives of overall design, basic hardware and software, component development, integration and verification. In response to the strong real-time and embedded characteristics of airborne fire control radar, key technologies urgently needed to be solved in this field of software radar have been studied. The key technologies include open system architecture, lightweight/ low-latency middleware, principles of component abstraction and division, efficient component development mechanisms, and model-driven component integration development environments. Then, the verification approach for airborne fire control software radar is discussed in terms of real-time performance, reconfigurability, and software decoupling. Finally, for the current situation that China has not yet equipped with airborne fire control software radar that fully meets the requirements of open architecture, some key problems that need to be focused on and solved are pointed out.
    Track Fusion Algorithm Based on Fully Convolutional Network with Multi-order Difference Loss
    YUN Tao, PAN Quan, YANG Jilong, HAO Yuhang, BAI Xianglong
    2024,46(2):62-69, DOI:
    [Abstract] (260) [HTML] (0) [PDF 7.86 M] (17)
    Abstract:
    To tackle the issue of previous track fusion algorithms′ heavy reliance on prior information, a track fusion algorithm based on fully convolutional network with multi-order difference loss is proposed. The various local tracks are subjected to spatiotemporal registration and track association at the fusion center. Through the design of the fully convolutional structure, the problems of large amount of parameters and difficult training caused by the use of fully connected layers in the traditional convolutional neural network model are avoided. Higher-precision fusion results are obtained by calculating the weighted loss of the track and its first- and second-order differences. The ablation experiments show that the track fusion algorithm proposed in this paper has a small model, strong convergence, high precision and moderate computing time. Simulation results confirmed that the algorithm proposed in this paper does not require any previous information. The proposed algorithm's fusion accuracy is better than the variance weighted fusion algorithm and the Kalman filter fusion algorithm when the noise parameters cannot be accurately estimated. The experimental results confirm the effectiveness and feasibility of the algorithm proposed in this paper.
    A Cooperative Target Detection Algorithm for Airborne Networked Radar
    LI Jieyu, CONG Xiaoyu, GUO Shanhong, SHENG Weixing
    2024,46(2):70-77, DOI:
    [Abstract] (246) [HTML] (0) [PDF 8.30 M] (14)
    Abstract:
    Joint target detection with networked radars can effectively improve the detection ability to stealth weak targets in complex electromagnetic jamming environment. However, it is especially hard to be netted for airborne radars due to the problems of large spatial registration error. In this paper, a cooperative target detection algorithm based on trajectory spatial registration is proposed for airborne networked radars systems. The maximum likelihood estimation generalized likelihood ratio detector is adopted for joint constant false-alarm rate(CFAR)detection of targets with the utilization of a small amount of range-Doppler domain data and target trajectory domain data under low detection threshold from radars nearby. Through the iterative calculation of spatial registration and joint CFAR detection, both of registration accuracy and joint target detection performance is improved. The results of numerical simulation experiments show that the spatial registration accuracy can be limited in a range-Doppler resolution cell. The detection probability is increased from 28. 5% for a single radar to 83. 67% for the four networked radars after iterative processing under the typical scenario with a signal-to-noise ratio of 9 dB after coherent integration and a false alarm probability of 10-4 when four radars are networked.
    A Fuzzy Fusion Rule-based CFAR Detector
    ZHANG Zhengwen, XIONG Xiaoze, LIAO Guisheng, GONG Pengcheng, ZHU Xinchao
    2024,46(2):78-85, DOI:
    [Abstract] (257) [HTML] (0) [PDF 7.93 M] (10)
    Abstract:
    Aiming at the performance limitations of the cell-averaged constant false alarm detector (CA-CFAR) in the presence of multi-target interference and clutter fringe effects, a constant false alarm detector (MCA-CFAR) based on the minimum selection cell in the sub-reference window is proposed. The performance of the detector is significantly improved by selecting the smallest cell in the sub-reference cell, and the detection probability, false alarm rate and detection threshold are derived in detail in the context of Rayleigh distribution. To further optimize the performance, a fuzzy logic fusion detector (FUMCA-CFAR) is designed, which uses two sensors to compute the spatial affiliation function values and fuses them by four rules, namely, algebraic sum, algebraic product, MAX, and MIN, to achieve a smooth output and reduce the loss of target information. Simulation experiments show that the FUMCA-CFAR detector based on algebraic sum fusion exhibits excellent detection performance and anti-jamming ability in both uniform and non-uniform backgrounds.
    A Study on Spatial Stabilization Algorithm of Airborne One-dimensional Phase Scanning Radar
    LIU Xincheng, ZHANG Linrang, ZHANG Tao
    2024,46(2):86-94, DOI:
    [Abstract] (263) [HTML] (0) [PDF 8.17 M] (11)
    Abstract:
    Traditionally, a hardware stabilized platform to maintain spatial stabilization of antenna scanning is frequently used by airborne radars. Nowadays, research on the usage of data processing method to achieve electronic stabilization in the scanning airspace is leading the development trend. In this paper, aiming at the problem of changes of the antenna beam pointing angle caused by the motion of airborne platform and the resulting decrease in detection accuracy or even the loss of the target, the method of beam steering to maintain spatial stabilization for one-dimensional phase scanning airborne radar is systematically discussed. The mathematical model of the directional angle transformation under the moving platform is established, and the formula of beam pointing angle transformation caused by the platform movement is deduced. The calculation method of one-dimensional phase scanning phase shift code is designed. The key technical indicators such as calculation accuracy, calculation time, beam pointing accuracy and the selection of phase shifter bits are verified by simulation. The results show that the spatial stabilization algorithm is effective and reliable, which provides a general design idea for the beam steering design of airborne phased array radar, and has great engineering significance and practical value.
    A Fast Coherent Integration Algorithm for Variable Acceleration Maneuvering Targets Based on TRT-SKT-HAF
    CHEN Kai, QIAO Liang, LI Ming, CHEN Hongmeng
    2024,46(2):95-102, DOI:
    [Abstract] (272) [HTML] (0) [PDF 16.19 M] (15)
    Abstract:
    When detecting high-speed maneuvering targets with radar, their motion characteristics can result in distance walking and Doppler migration, which hinders the accumulation of phase reference. To address the effects of target motion, various motion parameters are searched typically in traditional algorithms which increases computational requirements. In this paper, a fast phase parameter accumulation algorithm for variable acceleration targets based on time reversing transform (TRT)-second-order keystone transform (SKT)-high-order ambiguity function (HAF) is introduced to address the above issues. The SKT and TRT are used to compensate for walking distance. Phase compensation function constructed by HAF estimation of the target acceleration is used to compensate for Doppler migration. The proposed method has a computational complexity that is three orders of magnitude lower than the generalized Radon-Fourier transform, and does not require any parameter search. The simulation results demonstrate that the proposed method reduces the detection threshold by 5 dB in comparison to the Radon-fractional ambiguity function and exhibits superior detection performance at low signal-to-noise ratios.
    A Sequential Estimation Method of Pulse Repetitive Interval of Pulse Doppler Radar
    SHANG Wenxiu, YUAN Shuo, TA Shiying, LIU Zhangmeng
    2024,46(2):103-111, DOI:
    [Abstract] (266) [HTML] (0) [PDF 7.25 M] (8)
    Abstract:
    The evaluation variable control of the pulses was introduced to the scenario of sequential PRI estimation in this paper,enabling a higher-precision parameter estimation of pulse sequences contaminated with data noise such as missing and interference pulses. Furthermore, a probing integer division method was applied to the pulses within the buffer interval to track and detect the discontinuity moments of PRI switching in the pulse Doppler radar intercepted pulse sequence. Simulation experiments verified the effectiveness and superiority of the proposed sequential PRI estimation method compared to traditional PRI parameter estimation methods in sequential estimation scenarios.
    A Super-resolution-CFAR-Adaptive Reconstruction Algorithm for Range and Velocity Parameter of Frequency Agile Radar
    DENG Yucheng, WANG Feng, WANG Hao, WANG Jingjing
    2024,46(2):112-117, DOI:
    [Abstract] (251) [HTML] (0) [PDF 5.34 M] (10)
    Abstract:
    A super-resolution-constant false alarm(CFAR)-adaptive reconstruction algorithm suitable for sparse processing models in the range velocity dimension is proposed to address the problem of target parameter estimation and strong deception interference suppression in frequency agile radar. This algorithm achieves target search, range velocity parameter estimation and deception interference suppression. The distance velocity super-resolution spectrum based on quantized lattice points achieves the matching of target distance velocity parameters with dictionary elements, and uses the CFAR algorithm to perform two-dimensional search on the distance velocity plane to achieve target detection and distance velocity parameter estimation. The adaptive reconstruction cancellation method is used to subtract the estimated target components from the observation vector matrix. During the iteration process, the two-dimensional spectral noise subspace dimension is updated, and the distance velocity spectrum, CFAR, and adaptive cancellation are cyclically used to achieve the remaining target estimation. By using multi-objective estimation and cancellation during each iteration process, the problem of weak target parameter estimation under strong deception interference has been solved. An alternative approach to solve the underdetermined equation of the sparse representation is offered in the range and velocity dimensions for agile frequency radar.
    A Study on Anti-jamming Method Based on One-dimensional Range Profile
    HAO Xiaojun, ZHAO Hongyu, LI Tingpeng, LU Keyu
    2024,46(2):118-122, DOI:
    [Abstract] (256) [HTML] (0) [PDF 8.72 M] (19)
    Abstract:
    In domain of radar detection, great challenges are brought by all kinds of active jamming for single radar detection. In order to improve the anti-interference performance of single radar, according to the data of radar target echo, one-dimensional range profiles are calculated and used as label training data. The mature convolutional neural mapping network is introduced to construct the radar target recognition network through training by large numbers of false targets and real targets, and real radar target can be recognized easily from the large amount of IF data. At present, radar characteristic data is obtained through 3D modeling and simulation of CST software, small perturbation is added on the basis of simulating radar target echo samples for improving the robustness of network. Based on the increase of training data, the optimized radar target extraction network can make the radar more accurate.
    A Waveform Design Algorithm with High Doppler Tolerance Against Interrupted Sampling Repeater Jamming
    LI Zhanlei, HE Jinyang, CHENG Ziyang, HE Zishu
    2024,46(2):123-130, DOI:
    [Abstract] (278) [HTML] (0) [PDF 14.32 M] (10)
    Abstract:
    Interrupted sampling repeater jamming (ISRJ) is an active jamming for effectively deceiving coherent radar, especially for linear frequency modulated radar, whose received signal can generate a series of false targets after pulse compression. In order to counter this kind of jamming, meanwhile, considering the high Doppler tolerance requirement of waveform in the moving target scene, a waveform design algorithm based on ambiguity function is proposed in this paper. With the cognition of jamming in advance,an optimization model is established to idealized the correlation function of the waveform to design, and the constant modulus constraint for transmitted waveform is considered. Since the problem is non-convex, an alternate cycle algorithm is proposed to solve the problem. Eventually, the effectiveness of the proposed method is verified by simulation, and the waveform designed with high Doppler tolerance can effectively suppress the ISRJ. The method proposed is robust to the cognitive bias error of the jamming.
    A Study on Reinforcement Learning for Multi-radar Coexistence Anti-jamming
    ZHI Yongfeng, QIU Luying, ZHANG Long, GAO Honggang, SHI Haobo
    2024,46(2):131-137, DOI:
    [Abstract] (270) [HTML] (0) [PDF 7.24 M] (14)
    Abstract:
    Aiming at the problem that the multi-radar system cannot work under the frequency sweep interference of the environment,a multi-radar co-existence anti-jamming algorithm based on deep reinforcement learning is studied. In this paper, the environmentis divided into multiple sub-bands, the process of jamming occupying the frequency band is modeled, and the multi-radar system is modeled with Markov model. The double deep q-network (DQN) reinforcement learning algorithm is improved, and combined with the gating unit cyclic neural network, so that it can deal with the interference problem that depends on long time series.The deep deterministic strategy reinforcement learning algorithm based on gated recurrent memory is proposed, which improves the network overstaffing and large action set in double DQN reinforcement learning, and adopts the direct output action strategy to effectively reduce the network complexity. The simulation results show that in the case of multiple radar, the algorithm can not only reduce the interference from the outside world, but also reduce the interference between our own radars by avoiding the frequency points with interference.
    SAR Target Recognition Based on an Improved YOLOv5
    ZENG Xiangshu, HUANG Yifei, JIANG Zhongjin
    2024,46(2):138-145, DOI:
    [Abstract] (252) [HTML] (0) [PDF 35.81 M] (23)
    Abstract:
    An improved YOLOv5 network is proposed in this paper and is applied in SAR image target recognition. In order to optimize the performance of the network, three improvements are made as following. Firstly, width ratio and height ratio are used as the distance metric between labeled boxes, and k-means clustering method are used to generate a priori anchor box as the initial value of box size for prediction box optimization. Secondly, the regression loss function is improved in that CIoU is replaced by SIoU to improve the localization accuracy for densely distributed targets. Finally, the confidence loss function is improved in that binary cross entropy is replaced by Focal Loss to improve the target recognition accuracy in complex backgrounds. In this paper, based on the MSAR dataset, YOLOv3 and conventional YOLOv5 are selected as the comparison networks, and a large number of SAR image target recognition experiments are conducted. The experiment results show that the improved YOLOv5 network has higher recognition accuracy, recall rate, F1, AP and mAP for all types of targets compared with the two comparison networks.
    Imaging Simulation for Simultaneously Polarimetric Radar Based on Electromagnetic Computation
    CHEN Yun, ZHANG Yunhua, LI Dong
    2024,46(2):146-154, DOI:
    [Abstract] (272) [HTML] (0) [PDF 17.38 M] (16)
    Abstract:
    Electromagnetic (EM) simulation of radar signal is of great significance especially for the research of new mechanism radar systems. In this paper, a fast approach for EM echo simulation of simultaneously polarimetric radar (SPR) is proposed, based on which high-resolution radar imaging is conducted. Firstly, the wideband fully polarimetric EM scattering data was constructed base using FEKO software for a target under all incidences within 4π space. Then, the orthogonal complementary sequence waveforms are designed for the H and V transmission channels of SPR using majorization-minimization method to minimize the metric of complementary integral sidelobe level. Finally, the echo signals were assembled by calling the data base according to the specific angle and frequency ranges. To verify the proposed method, the F22 model is taken as the imaging target in the SPR simulation experiment, and the obtained fully polarimetric images were processed via Pauli decomposition, the influence from the imbalances of amplitude and phase between H and V channels was also analyzed.
    Design of Large Ultra Wideband Assembled Radome for Multi-band Synthetic Aperture Radar Antenna
    YANG Feilong, ZHU Jinbiao, LIU Yuquan, TANG Hongbiao, PAN Jie
    2024,46(2):155-159, DOI:
    [Abstract] (260) [HTML] (0) [PDF 9.01 M] (13)
    Abstract:
    An ultra-wideband radome design method is proposed for the complex configuration of multi-band synthetic aperture radar antennas with specific layout from P-band to Ka-band,which can meet the wideband efficient transmission for multiple antennas in different frequency bands with high inclination angles. According to the different layouts and frequency bands of the multi-band synthetic aperture radar antennas, a large assembled multi-layered radome with different permittivity combinations as the transmission areas is designed. The transmission coefficient of the radome manufactured by the proposed method is tested for the original layout of the multi-band synthetic aperture radar antenna under corresponding working conditions, and the results show that the radome would allow waves to penetrate efficiently in the ultra-wide band and fulfill the design requirements.
    Decoupling Technology of Airborne Microstrip Active Binary Array Antenna Based on Characteristic Mode Theory
    SI Wei, HAN Yanming, HAN Guodong
    2024,46(2):160-167, DOI:
    [Abstract] (285) [HTML] (0) [PDF 15.43 M] (15)
    Abstract:
    To solve the mutual coupling of the airborne microstrip active array antenna, a decoupling method based on characteristic mode analysis is proposed. In this method, the excited characteristic modes of the element are studied to distinguish between working and non-working modes firstly. Then, non-working modes contributing more to mutual coupling are obtained by studying the structure of the array, modal weighting coefficients, and modal characteristic far fields. Finally, non-working modes are suppressed while reducing the impact on working modes, thereby reducing the coupling while ensuring antenna performance. A microstrip antenna element of the band of 2. 19 GHz to 2. 32 GHz is designed. Non-working modes contributing more to mutual coupling are suppressed by shaping the patch of the element and adding metal columns in the element. Binary arrays before and after the improvement are compared. It can be seen that S12 in the entire band is reduced by more than 3 dB with acceptable gain drop and improvement of cross polarization. This method provides a new idea for effective decoupling of the airborne large-scale microstrip active array antenna.
    Select AllDeselectExport
    Display Method:
    Select AllDeselectExport
    Display Method:
    Testing Technology for Wafer Level Heterogeneous Integration Millimeter-wave Transceiver Module
    ZHANG Zhaohua, ZHANG Minghui, CUI Kai, HU Yongfang
    2023,45(8):91-96, DOI:
    [Abstract] (4809) [HTML] (0) [PDF 18.32 M] (49124)
    Abstract:
    Wafer level packaging (WLP) technology can significantly compress the volume and weight of the front-end transceiver module, realizing the miniaturization of active phased array radar. However, it also brings great challenges, such as heat management, channel isolation, signal cross-talk and adaptability of repairing and testing. Due to the introduction of more process steps and complex package architecture, how to test wafer level packaging modules to ensure yield and reduce testing costs has become an important technical issue. In this paper, the wafer level heterogeneous integration technology in millimeter-wave is summarized. Besides, the testing requirements and technical challenges, along with some integration solutions and testing process of typical products are deeply discussed. The existing key technologies are sorted out from three aspects: wafer level testing with probe station, socket testing and over the air (OTA) testing. It can provide some valuable references for the construction of radio frequency wafer level 3D packaging modules.
    Overview of Doppler Technology Based on Vortex Electromagetic Wave
    BU Lijun, XIE Wenxuan, ZHOU Yuang, ZHU Yongzhong
    2022,44(10):14-20, DOI:
    [Abstract] (5139) [HTML] (0) [PDF 12.48 M] (14567)
    Abstract:
    According to the basic theory of electromagnetic vortex wave, the properties of electromagnetic vortex waves are simulated and analyzed. Based on the uniform circular array model, the aliasing characteristics of the square Bessel function at the pitch Angle are verified. The principles and properties of linear Doppler, rotary Doppler and micro-Doppler are compared to show the advantages and disadvantages of vortex detection. The research progress of electromagnetic vortex wave Doppler detection in recent years is summarized, and the detection ability is verified by simulation. At the same time, the key problems in rotary Doppler and micro-Doppler detection are summarized, and the direction of further research is pointed out.
    Detection of Small Sea-surface Target Based on Random Forest in High-dimensional Feature Domain
    SHI Sainan, YANG jing, DONG Zeyuan
    2022(3):63-69, DOI:
    [Abstract] (5030) [HTML] (0) [PDF 12.78 M] (7389)
    Abstract:
    Feature detection is an effective way to improve the detection of small sea-surface targets. Aiming at the problems of low detection probability of low-dimensional features and difficult control of high-dimensional feature false alarms, a high-dimensional feature detection method based on random forest with controllable false alarms is proposed in this paper. First, multi-dimensional features are extracted from multiple domains of time domain, frequency domain, and time-frequency domain. The detection problem is converted into a two-class classification problem in high-dimensional feature space. Second, two types of balanced training samples including sea clutter and target echo are obtained by simulating returns with target. Third, random forest algorithm is introduced into high-dimensional feature space, and function expression of the splitting factor and the false alarm rate is established to obtain the control region of false alarm. Finally, it is verified by the IPIX measured data that the proposed detector has a certain performance improvement and meets the requirements of real radar with constant false alarm detection.
    Collaborative R & D Platform for Radar Based on Three-unified System
    PING Li-hao
    2011,33(3), DOI:
    [Abstract] (7866) [HTML] (0) [PDF 0.00 Byte] (1117)
    Abstract:
    Collaborative R&D platform on which processes,tools,data and knowledge were integrated was built through analyzing radar R&D problems.Unified design environment,unified process system,unified data space that composed radar R&D system were described.Three-tier structure of radar R&D platform was present.Management platform on collaborative tier provides the ability of task transition across organization and discipline.Design platform on application tier integrates knowledge and tool.Data platform on data tie...
    E-P-AMCBFM for Analysis of Electromagnetic Scattering by Hybrid Dielectric and PEC Objects
    ZHONG Shao-wei
    2011,33(3), DOI:
    [Abstract] (6734) [HTML] (0) [PDF 0.00 Byte] (902)
    Abstract:
    In computational electromagnetic field,the moment method based on surface integral equations for analysis of electromagnetic scattering by 3-D homogenous dielectric and PEC objects is a hot topic all through.In this paper,the EFIE integral equation is built on the surface and PMCHW integral equations is constructed based on the surface of homogenous dielectric object.Combined with adaptively modified characteristic basis function method(AMCBFM) that is based on dividing the object geometry into distinct blo...
    Sorties Determination for Targets with Non-rigid-structure via Narrowband Coherent Radar
    PENG Shi-bao, XU Jia, XIANG Jia-bin, PENG Ying-ning
    2011,33(3), DOI:
    [Abstract] (7050) [HTML] (0) [PDF 0.00 Byte] (878)
    Abstract:
    The sorties determination principle is discussed for narrowband coherent radar targets with non-rigid-structure based on a long coherent integration time in this paper.Firstly a novel signal model is proposed and some new concepts are put forward,such as common rotation Doppler,radial Doppler,chirp Doppler.And then it is pointed out that the initial frequency of target time-frequency distribution is decided by the sum of common rotation Doppler and radial Doppler,the trend is decided by chirp Doppler.Accord...
    Data Fusion System Modeling of Air-ground Cooperation Networking Aerial Defence
    ZHANG Ping-ding, ZHENG Kou-quan, WANG Rui
    2011,33(3), DOI:
    [Abstract] (7506) [HTML] (0) [PDF 0.00 Byte] (805)
    Abstract:
    Aiming at the complicated electromagnetic environment in informationization,Based on frame,function and character of the air-based command and control system and aerial denfence weapon network battle system,the concentrated,the distributed and the composite netting frame of the air-ground multi-sensor system fitting the dissimilar flat are proposed.Data fusion system model of the air-ground cooperation network aerial defense campaign system is constructed in this paper,which can improve the capability for a...
    A Method of Characteristic Analysis and Identification on Convolution Jamming
    GU Hai-yan, LU Gang, TANG Bin
    2011,33(3), DOI:
    [Abstract] (6918) [HTML] (0) [PDF 0.00 Byte] (797)
    Abstract:
    Convolution jamming has become an important jamming for its high utilizable efficiency of energy,admirable interference effect and flexible control.Based on the forming mechanisms,the interference performances and characteristics of different kinds of noise convolution jammings is analyzed.According to the difference of waveforms and phases between noise convolution jamming and ordinary pulse convolution jamming,the character factors are extracted,and then fuzzy pattern recognition has been used to recogniz...
    Application of Higher-order Statistic to Servo Drive System Fault Diagnosis
    卢雪林, 程望东
    2008,30(7), DOI:
    [Abstract] (5779) [HTML] (0) [PDF 0.00 Byte] (793)
    Abstract:
    对小波包分解和高阶统计量理论进行了阐述,提出一种基于高阶统计量特征和小波包分析相结合的雷达伺服传动系统故障诊断方法.当传动系统故障发生时,振动信号一般是非平稳和非高斯分布的信号,通常包含较强的噪声.用小波包分析对故障信号进行有针对性分解,并提取出故障特征频率带,然后运用高阶谱对故障特征信号进行分析,能够有效地实现故障诊断.
    Radar System State Comprehensive Evaluation Based on AHP and Fuzzy
    HUANG Jian-jun, YANG Jiang-ping, FANG Zi-cheng
    2011,33(3), DOI:
    [Abstract] (6830) [HTML] (0) [PDF 0.00 Byte] (787)
    Abstract:
    Radar system state evaluation involves many factors,and most of the factors have fuzzy uncertainty.On the basis of establishing evaluation index system,an evaluation method of radar system state based on analytic hierarchy process(AHP) and fuzzy is proposed in this paper.For the problem that multi-factor comparison matrix is difficult to meet consistency is achieved by transfer matrix theory,then the comprehensive weight of each index is obtained.Aiming at difference of various indexes,methods of measuring ...
    A Study on Relationship Between Target Detection Performance and Operation Frequency of HF Surface Wave Radar
    YANG Yun-sheng, XUE Wen-hu, BIAN Xiao-lin
    2011,33(3), DOI:
    [Abstract] (7313) [HTML] (0) [PDF 0.00 Byte] (766)
    Abstract:
    Because the operation frequency of high frequency surface wave radar(HFSWR) for target detection is selected by the monitoring of outside noise level,the optimal detection performance can not be achieved.To solve the problem,the multiple factors that affect the target detection performance are analyzed based on HF surface wave radar equation,and then a frequency selection method is presented by numerical simulation to calculate the relationship curve between SNR(SCR) and frequency.With the operation frequen...
    A New Algorithm of One-step Delay Based on Universal Tracking Initialization Model
    TAO Zhao-yang, WANG Sheng-li
    2011,33(3), DOI:
    [Abstract] (6893) [HTML] (0) [PDF 0.00 Byte] (764)
    Abstract:
    A new algorithm is proposed to solve the problem of quick target tracking initialization in clutter.The advantages of a new track initial model and one-step delay approach are integrated.An intermediate stage is added to the current common track initiation model.The one-step delay approach is used in processing the intermediate track.Two scan measurements is used for calculating the cumulative innovation and eliminating the false tracks.By this algorithm,the design flexibility is improved and that probabili...
    Characteristics and Application Analysis of Semiconductor Power Devices for Three Generations
    郑新
    2008,30(7), DOI:
    [Abstract] (6114) [HTML] (0) [PDF 0.00 Byte] (763)
    Abstract:
    以Si双极型功率晶体管为代表的第一代半导体功率器件和以GaAs场效应晶体管为代表的第二代半导体功率器件为雷达发射机的大规模固态化和可靠性提高做出了贡献.近年来以SiC场效应功率晶体管和GaN高电子迁移率功率晶体管为代表的第三代半导体--宽禁带半导体功率器件具有击穿电压高、功率密度高、输出功率高、工作效率高、工作频率高、瞬时带宽宽、适合在高温环境下工作和抗辐射能力强等优点.人们寄希望于宽禁带半导体功率器件来解决第一代、第二代功率器件的输出功率低、效率低和工作频率有局限性以至于无法满足现代雷达、电子对抗和通信
    Status of Ground-based Deep Space Exploration Network of USA and Its Revelation for China
    HAN Laihui
    2020,42(5):1-8, DOI:
    [Abstract] (5106) [HTML] (0) [PDF 29.21 M] (759)
    Abstract:
    To meet the requirement of the deep space exploration of China, the planet radar equipment development is suggested to enhance the deep space exploration system based on its recent working mode. The ground-based deep space expoloration network of USA adopts deep space telemetry, track and command network, very long baseline array network and ground-based planet radar. By calling different equipments, different working modes can be formed, and all equipemnts are used with high efficiency. Modes of deep space exploration of USA are investigated and constituting programming of ground-based planet radar and research of key techniques are suggested. The purpose is to provide support and reference for China's deep space exploration in the future.
    A Method for PD Radar Dim Target Detection Based on Stochastic Resonance Principle
    LIU Wei, LU Zai-qi, ZHU Yi-long
    2011,33(3), DOI:
    [Abstract] (7015) [HTML] (0) [PDF 0.00 Byte] (758)
    Abstract:
    Dim signal detection is chanllenging due to the fact that the signal is submerged by the powerful sidelobe clutter,while the pulse Dopple(PD) radar is following the target.Stochastic resonance principle is made good use of to improve the signal noise ratio and the detection performance.Firstly,the basic principle of stochastic resonance is introduced,and the frequency spectrum characteristic of the return signals is analyzed while the radar is after the target.Then a novel approach based upon stochastic res...
Search
Key Item
Keyword
Search
External Links
Rohde & Schwarz InternationalCNKITektronix
Archive

You are the visitor to this site

Address：

Postcode：210039 Fax：025-51821053

ServiceTel：025-51821080/81/83/85/86/88 E-mail：modernradar@126.com

Modern Radar ® 2024 All Rights Reserved