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2023 IEEE International Workshop on Electromagnetics: Applications and Student Innovation Competition, iWEM 2023

作者： Xiaofei, Shi Jiaxin, Shi Jiaqi, Liu Zhongyi, Fang Lei, Wang Lizhong, Song Shandong Institute of Space Electronic Technology Yantai264003 China Harbin Institute of Technology School of Electronics and Information Engineering Harbin150001 China Harbin Institute of Technology at Weihai School of Information Science and Engineering Weihai264209 China Beijing Institute of Space Long March Vehicle National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematics Beijing100076 China Shandong Huayu Aerospace Technology Co. Ltd Yantai264003 China

ISBN: (纸本)9798350336740

This paper designs an array antenna with a planar printed structure. The antenna element adopts a rectangular slot antenna, and the antenna element is excited by a T-shaped feeding structure. The microstrip power distribution network is used to feed the antenna radiator array with equal power. The microstrip power distribution network and slot radiator array are located on top and bottom of dielectric substrate, and the array antenna is implemented by use of the printed circuit technology. In order to improve the gain, a metal reflector ground is placed below the dielectric substrate. A planar printed slot array antenna working in X band is designed. The coaxial line is used to feed the array antenna at the bottom. The whole antenna structure is easy to feed and suitable for fabrication. The designed array antenna was numerically calculated using full wave electromagnetic simulation software. At a working frequency of 10.1GHz, the voltage standing wave ratio (VSWR) of the antenna is about 1.35, and the gain is about 21.46dB. The design of the antenna scheme can be used as a reference for the actual application of engineering. © 2023 IEEE.

关键词： Slot antennas

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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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INTRA-PULSE MODULATION FEATURE ANALYSIS AND PARAMETER ESTIMATION OF PHASE AND FREQUENCY MULTI-MODULATION SIGNAL

INTRA-PULSE MODULATION FEATURE ANALYSIS AND PARAMETER ESTIMA...

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IET International Radar Conference 2023, IRC 2023

作者： Xue, Chenle Jiang, Zhiye Ren, Lixiang Fan, Huayu Liu, Quanhua Radar Research Lab School of Information and Electronics Beijing Institute of Technology Beijing100081 China Key Laboratory of Electronic and Information Technology in Satellite Navigation Beijing Institute of Technology Ministry of Education Beijing100081 China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing Institute of Space Long March Vehicle Beijing100076 China Yangtze Delta Region Academy of Beijing Institute of Technology Jiaxing314019 China Chongqing Innovation Center Beijing Institute of Technology Chongqing401120 China

ISBN: (纸本)9781839539954

The parameter inversion of multi-modulation waveforms has always been a key and difficult problem in the field of electronic reconnaissance. To solve this problem, a method for intra-pulse modulation feature analysis and parameter estimation of phase and frequency multi-modulation signal is proposed in this paper. Firstly, we apply square preprocessing to eliminate the binary phase coded modulation information. Then, subpulse separation and subpulse parameter estimation are achieved by using the smooth pseudo-Wigner Ville distribution (SPWVD) and wavelet transform. Moreover, histogram statistics are introduced to improve the robustness of the method. Finally, the N-order phase difference is proposed for recovering binary phase coded sequences. Frequency domain filtering and sliding window averaging are also added to further improve the applicability of the proposed method under low signal-to-noise ratio (SNR) conditions. Simulation results suggest that the method proposed in this paper can achieve accurate signal inversion and has good robustness. © The Institution of Engineering & technology 2023.

关键词： Wigner-Ville distribution

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Scalings for the Alfvén-cyclotron instability in a bi-kappa plasma

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Earth and Planetary physics 2023年第6期7卷 631-639页

作者： YueQun Lou Xing Cao MingYu Wu BinBin Ni TieLong Zhang Shenzhen Key Laboratory of Numerical Prediction for Space Storm Institute of Space Science and Applied TechnologyHarbin Institute of TechnologyShenzhen 518055China Key Laboratory of Solar Activity and Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China Department of Space Physics School of Electronic InformationWuhan UniversityWuhan 430072China Chinese Academy of Sciences Center for Excellence in Comparative Planetology Hefei 230026China Space Research Institute Austrian Academy of SciencesGraz 8042Austria

The particle velocity distribution in space plasma usually exhibits a non-Maxwellian high-energy tail that can be well modeled by kappa *** this study,we focus on the growth rates of the Alfvén-cyclotron instability driven by ion temperature anisotropy in a kappa *** solving the kinetic linear dispersion equation,we explore the sensitivity of growth rates to the spectral indexκof a bi-kappa distribution under different plasma conditions,including a variety of plasma beta β_(hp) and temperature anisotropy A_(hp) values of hot ***,a concise,analytic scaling formula is derived that relates the dimensionless maximum growth rate to three independent variables:the spectral index and the plasma beta and temperature anisotropy of hot *** results show that as theκ-value increases,the instability bandwidth narrows and the maximum growth rate increases *** higherβ_(hp)and A_(hp)′the maximum instability undergoes a sharp increase as *** our fits of dimensionless maximum growth rates are compared with solutions to kinetic linear dispersion theory,the results generally exhibit good agreement between *** under the circumstances of largeκ-values and highβ_(hp)and A_(hp)′the scalings of maximum growth rates primarily accurately model the numerical *** analytic expressions can readily be used in large-scale models of the Earth’s magnetosphere to understand wave generation due to the Alfvén-cyclotron instability.

关键词： Alfvén-cyclotron instability kappa distribution kinetic linear dispersion theory scaling formula

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1-bit Coding Metasurface for Wideband RCS Reduction

1-bit Coding Metasurface for Wideband RCS Reduction

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International Applied Computational Electromagnetics Society Symposium (ACES)

作者： Yinfang Xu Jiaqi Liu Lu Gao Xia Ai Zhongjie Zhang Huan Liang National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematics Beijing Institute of Space Long March Vehicle Beijing China

This paper achieve efficient RCS reduction over a wide frequency range by exploiting the reflection properties of the coding metasurface. The metasurface consists of “0” cells and “1” cells, and the reflection phase difference is close to 180° over a wide frequency range. By designing the spatial random coding arrangement of “0” units and “1” units, the electromagnetic waves incident on the metasurface form diffuse reflection, so as to achieve the purpose of broadband RCS reduction. The simulation results show that when the incident wave is irradiated vertically, the metasurface can basically achieve a RCS reduction of more than 10dB in a wide frequency band of 10-20.5GHz compared to a metal plate of the same size. In the case of oblique incidence, the RCS reduction still has a good effect, which is basically the same as the curve at normal incidence, and has the characteristics of wide-angle incidence RCS reduction. The reduced bandwidth of the broadband RCS of the coding metasurface is basically consistent with the 10 dB polarization bandwidth of the cell structure. The design of the metasurface is simple and efficient, so it has great application potential in stealth new technologies and new materials.

关键词： Electric potential Simulation Electromagnetic scattering Metals Metasurfaces Computational electromagnetics Reflection

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Intelligent Assignment Strategy for Multi-Target Adversarial Interception

Intelligent Assignment Strategy for Multi-Target Adversarial...

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2022 Chinese Automation Congress, CAC 2022

作者： Yu, Yang Fang, Yizhong Wu, Han Han, Tuo Hu, Qinglei Beihang University School of Automation Science and Electrical Engineering Beijing100191 China Beijing Institute of Space Long March Vehicle National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematics Beijing100076 China Beihang University School of Aeronautic Science and Engineering Beijing100191 China Hangzhou310023 China

ISBN: (纸本)9781665465335

The multi-missile confront multi-target is a classic target allocation issue in the combat scenario of multiple missiles intercepting multiple maneuvering targets. Traditional algorithms lack environmental assessment model, train quality, and indicator function in the adversarial environment. To this end, this paper aims to propose an intelligent assignment strategy which contains indicator function and evaluation model. Then, an indicator function and an evaluation model considering the miss distance, threat situation, and the number of specified interception targets are introduced into the reinforcement learning algorithm. The local and global reward functions are introduced to improve the training convergence and efficiency in the multi-missile multi-target confrontation scenario. Finally, simulation results are designed to check on advantage of intelligent allocation strategy. © 2022 IEEE.

关键词： Reinforcement learning

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Dual-Frequency Vortex Beam Generation Using Coding Metasurface

Dual-Frequency Vortex Beam Generation Using Coding Metasurfa...

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2022 International Applied Computational Electromagnetics Society Symposium, ACES-China 2022

作者： Li, Junfeng Kong, Xianglin Wang, Fengjun Miao, Zhuowei Wang, Xiaoyi Shen, Xiaopeng Zhang, Shengjun Zhao, Lei China University of Mining and Technology School of Information and Control Engineering Xuzhou China National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematical Beijing China Polytechnique Montreal Department of Electrical Engineering MontrealQC Canada China University of Mining and Technology School of Materials Science and Physics Xuzhou China

ISBN: (纸本)9781665452366

This paper presents a dual-frequency coding metasurface (CM) for vortex beam generation. The metasurface unit cell is realized with two symmetric metal layers separated by a dielectric substrate. Each metal layer consists of an outer square ring, a middle square ring, and an inner rhombus patch. Two out-of-phase transmitting states in two bands are achieved by rotating the inner rhombus patch by 90 °. Two 1 = + 2 vortex beams are then realized in two different bands by properly distributing the two states on the metasurface aperture. A metasurface with 30 × 30 elements is designed, simulated, and experimentally demonstrated. The experimental results agree well with the simulating ones, showing that the metasurface achieves a high transforming efficiency in both Ku (13.6-14.8GHz) band and Ka (26.7-27.7 GHz) band. © 2022 IEEE.

关键词： Kurchatovium

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Perturbation Estimated Incremental Guidance for Exo-Atmospheric Interception

Perturbation Estimated Incremental Guidance for Exo-Atmosphe...

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2022 Chinese Automation Congress, CAC 2022

作者： Lu, Yuting Liu, Peng Han, Tuo Hu, Qinglei Beihang University School of Automation Science and Electrical Engineering Beijing100191 China Beijing Institute of Space Long March Vehicle National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematics Beijing100076 China Beihang University School of Aeronautic Science and Engineering Beijing100191 China Hangzhou310023 China

ISBN: (纸本)9781665465335

In order to meet the requirement of accurate intercept against the increased target maneuverability and external disturbance, a second-order inertial delay based incremental guidance law (IDIASMG) is proposed for an exo-atmospheric interceptor. Specifically, a three-dimensional guidance model is transformed into an incremental version. As a guidance design benchmark, a conventional sliding mode guidance law (SMG) is presented, and a sliding mode incremental guidance law (ISMG) is designed with gain adaptation. Moreover, a second-order inertial delay filter is utilized to estimate and compensate guidance perturbation including the target maneuver, system uncertainty, and external disturbance. Theoretical analysis shows that the incremental guidance requires smaller gains to ensure smaller system residual than the conventional SMG. Extensive numerical simulations validate the effectiveness and robustness of IDIASMG. © 2022 IEEE.

关键词： Uncertainty analysis

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Computational uncertainty and optimal grid size and time step of the Lax-Friedrichs scheme for the 1D advection equation

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Atmospheric and Oceanic science Letters 2023年第3期16卷 46-51页

作者： Jing Cao Jianping Li Yanjie Li College of Science Tianjin University of TechnologyTianjinChina Frontiers Science Center for Deep Ocean Multispheres and Earth System/Key Laboratory of Physical Oceanography/Academy of the Future Ocean/Innovation Center for Ocean Carbon Neutrality Ocean University of ChinaQingdaoChina Laboratory for Ocean Dynamics and Climate Pilot Qingdao National Laboratory for Marine Science and TechnologyQingdaoChina State Key Laboratoryof Numerical Modelingfor Atmospheric Sciences and GeophysicalFluid Dynamics Instituteof Atmospheric PhysicsChinese Academyof SciencesBejingChina

本文对于应用Lax-Friedrichs格式数值求解一维平流方程,研究数值求解过程中产生的截断误差与舍入误差,以及两种误差逐层向高时间层传播的累积,得到新的数值解总误差上界的理论近似公式,以及最优格距和最优时间步长的理论公式.通过数值... 详细信息

本文对于应用Lax-Friedrichs格式数值求解一维平流方程,研究数值求解过程中产生的截断误差与舍入误差,以及两种误差逐层向高时间层传播的累积,得到新的数值解总误差上界的理论近似公式,以及最优格距和最优时间步长的理论公式.通过数值算例验证了所得公式的可靠性。然后,发现了两种不同机器精度下最优时间步长之比满足的一个仅与机器精度有关的普适关系.最后,理论验证了在网格比固定的情况下,此问题满足数值计算的不确定性原理,以及在机器有限精度下最优时间步长的必然存在。

关键词： Lax-Friedrichs格式数值计算的不确定性原理最优格距最优时间步长普适关系

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Design of a Printed Monopole Array Antenna with the Simple Feeding Structure

Design of a Printed Monopole Array Antenna with the Simple F...

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2023 International Applied Computational Electromagnetics Society Symposium, ACES-China 2023

作者： Xiaofei, Shi Yizhuo, Liu Jiaqi, Liu Yizhong, Fang Zhiwei, Gao Lei, Wang Lizhong, Song Shandong Institute of Space Electronic Technology Yantai China School of Electronics and Information Engineering Harbin Institute of Technology Harbin150001 China School of Information Science and Engineering Harbin Institute of Technology at Weihai Weihai264209 China Beijing Institute of Space Long March Vehicle National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematics Beijing100076 China School of Information Science and Technology Shijiazhuang Tiedao University Shijiazhuang050043 China Shandong Huayu Aerospace Technology Co.Ltd Yantai264003 China

ISBN: (纸本)9781733509657

This paper introduces an array antenna by use of printed monopole antennas as element. The designed array antenna consists of two layers of dielectric substrate and a metal reflective ground. The array antenna element adopts trapezoidal printed monopole antenna, and the element is fed by coplanar waveguide (CPW). The array antenna radiator is located on the top of the upper dielectric substrate, and the feeding microstrip power divider network is located on the bottom of the lower dielectric substrate. The antenna element radiator is vertically connected to the microstrip feeding power divider network in a coaxial-like manner. The whole structure of the antenna is simple, and the feeding structure is convenient, which makes it suitable for fabrication and assembly. A printed 4x4 monopole array antenna was designed and the relevant simulated results are provided. The simulation results show that at the 10GHz, the designed array antenna has a gain of approximately 12.73 dB and a return loss of approximately -11.75 dB. The antenna scheme discussed in this paper can provide technical reference for the design of planar printed array antennas. © 2023 Applied Computational Electromagnetics Society (ACES).

关键词： Microstrip antennas

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