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IET International Radar Conference 2015

作者： L. Gao Z. Y. Jiang J. Q. Liu H. Y. Liu J. L. Bai F. Xu H. Li S. Y. Chen L. Sun Y. B. Bian J. Wang Y. S. He National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics P.O. box 9200 Beijing 100076 China Chinese Academy of Sciences Beijing Beijing CN

ISBN: (纸本)9781510822023

This paper presents a development of a narrowband hightemperature superconducting filter with high selectivity. The center frequency of this filter is 8.625 GHz and the 3 dB bandwidth is 156 MHz (a fractional bandwidth of 1.81 %). In order to achieve high band edge steepness, we introduce a 10-resonator quasi-elliptic function response with two pairs of transmission zeros in the cascaded quadruplet coupling structure. The filter was manufactured on a 2-in-diameter 0.5-mm-thick MgO wafer with double-sided YBCO films. The measured results show a midband insertion loss of 0.58 dB and a return loss better than 16 dB. Band edge steepness reaches over 3.82 dB/MHz at both the high and low frequency edges. The 60 dB rectangle ratio is less than 1.19. The out-of-band rejection is over 60 dB at 17.8 MHz from the 3 dB band edge.

关键词： High-temperature superconducting (HTS) X-band microwave filter transmission zeros

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Performance test of Fourier transform infrared imaging spectrometer

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Guangxue Jingmi Gongcheng/Optics and Precision Engineering 2015年 23卷 190-196页

作者： Li, Jian-Hua Xue, Feng Xue, Lian Li, Zhi-Feng Liu, Jia-Qi National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematics Beijing100076 China

The paper researches the measurement methods of key parameters of Fourier transform imaging spectrometers. Firstly, the physical meaning of the key parameter Noise Equivalent Spectral Radiance (NESR) was introduced and corresponding calculation model, test principle and data processing method were given. Then, a calibrated black body was used as radiation source, the performance parameters of Fourier transform imaging spectrometer for mid-wavelength and long-wavelength were tested experimentally, including the NESR, radiometric accuracy and spectral errors. test results show that the average NESRs of infrared imaging spectrometer for long-wavelength at 10 μm is 21.4 nW/(cm2·sr·cm-1) and that for mid-wavelength at 4.6 μm is 4.6 nW/(cm2·sr·cm-1). The radiometric accuracies of the spectrometer is less than 0.4 K and 2 K for long-wave and mid-wave, respectively. The spectral errors of the spectrometer for both mid-wavelength and long-wavelength are less than half of the spectral resolution. These parameters are all in the normal range, which verifies the feasibility of test method. It provides references for the periodically measurement of imaging spectrometers. © 2015, Chinese Academy of sciences. All right reserved.

关键词： Temperature measurement

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Isotope-Shift Measurement of Bosonic Yb^(+)Ions

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Chinese physics Letters 2023年第9期40卷 43-47页

作者：乐虹伶邵虎陈正方鹏程曾孟彦张宝林黄垚李冀光陈群峰管桦高克林 State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Innovation Academy of Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430071China University of the Chinese Academy of Sciences Beijing 100049China Key Laboratory of Atomic Frequency Standards Innovation Academy of Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430071China Institute of Applied Physics and Computational Mathematics Beijing 100088China Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences University of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China Wuhan Institute of Quantum Technology Wuhan 430206China

We present a method that the atomic transition frequency measurement relies on the accurate wavemeter,optical frequency comb and stable Fabry–Pérot cavity to precise determination of stable even isotope shift on single Yb+ion(A=168,170,172,174,176).The 6s^(2)S_(1/2)←→6p^(2)P_(1/2)and 5d^(2)D_(3/2)←→6s^(3)[3/2]_(1/2)resonance dipole transition frequencies are preliminarily measured by using a wavemeter which is calibrated by the 729 nm clock laser of ^(40)Ca^(+).Meanwhile,those frequencies are double checked by using optical frequency comb for correction of ***,by changing frequency locking points at an ultralow expansion cavity more slightly and monitoring the corresponding atomic fluorescence changing with 17%,we finally improve the resonant frequency uncertainty to±6 MHz,which is one order of improvement in precision higher than previously published measurements on the same transitions.A King-plot analysis with sensitivity to coupling between electrons and neutrons is carried out to determine the field and mass shift *** measurement combined with existing or future isotope shift measurements can be used to determine basic properties of atomic nuclei,and to test new forces beyond the Standard Model.

关键词： checked correction resonant

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Topology Optimization of Complex Network based on NSGA-II

Topology Optimization of Complex Network based on NSGA-II

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IEEE Advanced Information technology, Electronic and Automation Control Conference (IAEAC)

作者： Zhang Bin Gan Zhi-chun Chen wen Hu Qiang-qiang Hou Jian-feng Departments of information and communication National University of Defense Technology China Science and Technology on Test Physics & Numerical Mathematic Laboratory China

This paper proposes a complex network topology optimization method based on NSGA-II with degrees and edges number unchanged. The method selects the elite parent networks by applying non-dominated layer sorting and congestion degree calculation through the network crossover and mutation operation to achieve maximum network efficiency and network invulnerability. Simulation analysis shows that the method can significantly improve the invulnerability and network efficiency of the initial networks at the same time. Optimizing the network efficiency makes the network connection show a negative correlation. The network presents a "multi-core decentralized" structure; optimizing the network invulnerability makes the connection show a positive correlation, the network presents a "close core and scattered periphery" structure; the cooperative optimization makes the network present a "tighter core and large periphery" structure, which is proved with good theoretical generality and practical application value.

关键词： Optimization Sociology Complex networks Correlation Topology

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An Improved DSDV Protocol based on Link Stability with Adaptive Period for Intra-cluster Routing in High-dynamic Flying UAV Networks

An Improved DSDV Protocol based on Link Stability with Adapt...

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International Applied Computational Electromagnetics Society Symposium (ACES)

作者： Yiguo Zhang Lai Qian Xiaoqin Xue Wei Wang College of Computer Science Xi’an Polytechnic University Xi’an China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing Institute of Space Long March Vehicle Beijing China

We propose a stability-based adaptive-period DSDV intra-cluster routing protocol that automatically adjusts the routing update period by the link stability among the nodes in the cluster structure, thus reducing the network overhead of the network structure in maintaining the routing table. We describe the link stability and adaptive period implementation and test the proposed routing protocol in the cluster structure based on network simulation. The implementation results show that the proposed routing protocol has better performance than the traditional DSDV routing protocol, can improve the network throughput and reduce the routing overhead in the network, and has good adaptability in the cluster with fast changing network topology.

关键词： Costs Adaptive systems Network topology Routing Throughput Computational electromagnetics Routing protocols

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Statistical analysis and simulation method of forward scattering clutter in bistatic radar

Statistical analysis and simulation method of forward scatte...

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IET International Radar Conference 2013

作者： Zhang, Chuan-Fang Liu, Chang-Jiang Hu, Cheng Liu, Xiang-Rong Beijing Institute of Technology School of Information and Electronics Beijing 100081 China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematical Beijing China

ISBN: (纸本)9781849196031

The research of statistical properties and simulation methods of radar clutter have vital importance to the design, simulation and development of radar systems. Based on the analysis of some experimental data of forward scattering radar (FSR) clutter, it was found that under low wind speed and narrow dynamic range, the amplitude of FSR clutter was subject to K distribution;while under high wind speed or wide dynamic range, it was subject to lognormal distribution;the clutter power spectrum was subject to the fourth-order all-pole model. With the above statistical analysis, the forward scatter coherent clutter was simulated using a method combining zero-memory nonlinear transformation with spherically invariant random process. The statistical characteristics of the simulated clutter were identical to those of the measured clutter, which verified the validity of this method.

关键词： Radar clutter

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Characteristic Mode Design of Dual-Band Multistate Tunable Absorber Based on Programmable Flexible Metasurface

TechRxiv

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TechRxiv 2022年

作者： Li, Mengmeng Ning, Zihao Ding, Dazhi Ai, Xia Liu, Jiaqi Wang, Chao-Fu The Department of Communication Engineering Nanjing University of Science and Technology Nanjing China The National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing100076 China The Department of Electrical and Computer Engineering National University of Singapore Singapore

Theory of characteristic modes (TCM) is applied to the design of a programmable flexible metasurface (PFMS) to achieve its multistate tunable microwave absorption. The designed metasurface consists of two layers. The first layer is a very thin polyimide (PI), on which unit cells consisting of two trapezoidal patches symmetrical along the central bias microstrip are printed. The second layer is grounded polyvinyl chloride (PVC) substrate to maintain the flexibility of the designed structure. The TCM is used to analyze and understand the modal behavior of the unit cell, which provides clear underlying electromagnetic (EM) physics to guide us how to load positive-intrinsic-negative (PIN) diode as a tunable resistance to achieve variable absorption states. The designed PFMS absorber have been fabricated and experimentally verified on the flat and cylindrical foams, respectively. Good agreements can be found for both planar and cylindrical metasurface structures between full-wave simulations and measurements. Less than -10 dB reflectivity is achieved from 3.6 to 10.7 GHz (99%). The mimicry of time-varying scattering cross section (SCS) is further realized through real-time coding PFMS absorber, which can be precisely tuned from -30 dB to 0 dB with a step of 1.5 dB at 5.5 GHz and 10.4 GHz, respectively. © 2022, CC BY.

关键词： Polyvinyl chlorides

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Research on Heterogeneous Parallel Algorithms for Radar Signal Processing in OpenCL Platform

Research on Heterogeneous Parallel Algorithms for Radar Sign...

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International Applied Computational Electromagnetics Society Symposium (ACES)

作者： Yingfei Wang Xiaoqin Xue Wei Wang Department of Computer Science Xi’an Polytechnic University Xi’an China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing Institute of Space Long March Vehicle Beijing China

An efficient radar signal processing parallel algorithm for Open Computing Language (OpenCL) is presented in this paper, which reveals a rational allocation schema of tasks between the central processing unit (CPU) and the graphics processing unit (GPU). The powerful parallel processing ability of GPU is used to replace the traditional serial processing method by the way of pipeline acceleration and algorithm parallel acceleration, and the real-time performance of the proposed algorithm is improved by the design idea of intra-module parallelism and inter-module flow processing. The algorithm is applied to CPU-GPU heterogeneous computing platform and has a good portability. The effectiveness and real-time performance of the algorithm are verified through simulation data.

关键词： Signal processing algorithms Graphics processing units Radar signal processing Real-time systems Heterogeneous networks Central Processing Unit Resource management

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Cone-Shaped Space Target Inertia Characteristics Identification by Deep Learning with Compressed Dataset

TechRxiv

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TechRxiv 2022年

作者： Li, Mengmeng Wang, Shaoran Yang, Tian Ai, Xia Liu, Jiaqi Andriulli, Francesco P. Ding, Dazhi Department of Communication Engineering Nanjing University of Science and Technology Nanjing China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing100076 China Politecnico di Torino of Turin Turin Italy

An effective method for identifying inertia characteristics of cone-shaped space target based on deep learning is proposed. The inertia ratio is determined by the time-varying scattering fields from the cone-shaped targets. The multistatic method is introduced to reduce the evaluation time of time-varying scattering fields. The micro-Doppler spectrogram (MDS) dataset is constructed by time-frequency analysis with numerical simulation method, point scattering model, and experimental tests. The compressed dataset is further achieved by truncated singular value decomposition (SVD). Finally, the micro-motion parameter identification model is constructed to identify the inertia ratio for the cone-shaped space target. The interaction loss function and the feed-forward denoising convolutional neural networks (DnCNNs) are employed to improve the identification accuracy. Parameters identification of the precession frequency, precession angle, spin frequency, and inertia ratio with both simulation and experiment datasets demonstrate the validity of the proposed method. © 2022, CC BY.

关键词： Singular value decomposition

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Electromagnetic scattering characteristics of the plasma sheath around Re-entry hypersonic vehicles

Electromagnetic scattering characteristics of the plasma she...

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IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP)

作者： Run-hui Wu Jia-qi Liu Gang Meng Xin Liu Ai-min Ren Xia Ai Song Chai Ju-yan Zhao Ya-nan Li Ming-liang Wang National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematical No.1 Dahongmen South Road Fengtai District Beijing 100076 China

ISBN: (纸本)9781538616093

In order to analyze electromagnetic scattering of reentry vehicle, models of the expected electromagnetic scattering properties of the aircrafts must be developed. This paper begins with a discussion of the plasma sheath characteristics, and the interactions between electromagnetic wave and plasma sheath, and the simulation model of plasma sheath scattering is described by using physical optics and hierarchical approximation technique. Then rigorous calculations of radar cross section(RCS) for a double conical target, plasma-clad body, 30km, 40km, 50km altitude, 4km/s, 5km/s velocity are presented in context with 9.8GHz, 5.8GHz, 3.2GHz, 1.5GHz of incident wave frequency. The results are shown that plasma sheath can increase or decrease the RCS of vehicles for different altitude, velocity and wave frequency. When the aircraft has a low altitude and high-speed flight, electron density of plasma sheath will increase continuously. Influenced by it, the RCS of vehicles shows a decreasing trend.

关键词： Plasma sheaths Electromagnetic scattering Atmospheric modeling Mathematical model Radar cross-sections

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