检索结果-南通市图书馆

A Survey on Channel Measurements and Models for Underground MIMO Communication Systems

在线全文

学校读者我要写书评

暂无评论

China Communications 2023年第8期20卷 103-119页

作者： Asad Saleem yejun he Guoxin Zheng Zhining Chen State Key Laboratory of Radio Frequency heterogeneous Integration Guangdong Engineering Research Center of Base Station Antennas and PropagationShenzhen Key Laboratory of Antennas and PropagationCollege of Electronics and Information EngineeringShenzhen UniversityShenzhen 518060China Key Laboratory of Specialty Fiber Optics and Optical Access Networks Shanghai UniversityShanghai 200444China Department of Electrical and Computer Engineering National University of SingaporeSingapore

The high reliability of the communication system is critical in metro and mining applications for personal safety,channel optimization,and improving operational *** paper surveys the progress of wireless communication systems in underground environments such as tunnels and mines from 1920 to 2022,including the evolution of primitive technology,advancements in channel modelling,and realization of various wireless propagation *** addition,the existing and advanced channel modeling strategies,which include the evolution of different technologies and their applications;mathematical,analytical,and experimental techniques for radio propagation;and significance of the radiation characteristics,antenna placement,and physical environment of multiple-input multiple-output(MIMO)communication systems,are *** given study introduces leaky coaxial cable(LCX)and distributed antenna system(DAS)designs for improving narrowband and wideband channel *** paper concludes by figuring out open research areas for the future technologies.

关键词： leaky coaxial cable(LCX) long-term evolution for metro(LTE-M) multiple-input multipleoutput(MIMO)systems propagation modeling

A Compact Ultra-Wideband Circularly Polarized Antenna Array for Vehicular Communications

在线全文

学校读者我要写书评

暂无评论

China Communications 2023年第6期20卷 310-320页

作者： Wei he yejun he Long Zhang Jun Hong Haixia Cui Amir Boag School of Electrical and Information Engineering Hunan Institute of TechnologyHengyang 421002China College of Electronics and Information Engineering Shenzhen UniversityShenzhen 518060China School of Physics and Telecommunication Engineering South China Normal UniversityGuangzhou 510630China School of Electrical Engineering Tel Aviv UniversityTel Aviv 69978Israel

In this paper,a new compact ultrawideband(UWB)circularly polarized(CP)antenna array for vehicular communications is *** antenna array consists of a 2×2 sequentially rotated T-shaped cross dipole,four parasitic elements,and a feeding *** loading the T-shaped cross dipoles with parasitic rectangular elements with cut corners,the bandwidth can be *** this basis,the radiation pattern can be improved by the topology with sequential rotation of four T-shaped cross-dipole antennas,and the axial ratio(AR)bandwidth of the antenna also can be further *** addition,due to the special topology that the vertical arms of all Tshaped cross dipoles are all oriented toward the center of the antenna array,the gain of proposed antenna is improved while the size of the antenna is almost the same as the traditional cross *** and measured results show that the proposed antenna has good CP characteristics,an impedance bandwidth for S11he 3-d B AR bandwidth of about 104.1%(3.17:1,1.57-4.98 GHz),a wide 3-d B gain bandwidth of 73.3%as well as the peak gain of 8.6 d Bic at 3.5 *** overall size of antenna is 0.56λ×0.56λ×0.12λ(λrefers to the wavelength of the lowest operating frequency in free space).The good performance of this compact UWB CP antenna array is promising for applications in vehicular communications.

关键词： circularly polarized antenna vehicle satellite communications cross-dipole antenna ultrawideband(UWB)antenna

An Overview of Terahertz Antennas

在线全文

学校读者我要写书评

暂无评论

China Communications 2020年第7期17卷 124-165页

作者： yejun he Yaling Chen Long Zhang Sai-Wai Wong Zhi Ning Chen Guangdong Engineering Research Center of Base Station Antennas and Propagation Shenzhen Key Laboratory of Antennas and PropagationCollege of Electronics and Information EngineeringShenzhen UniversityShenzhen 518060China Department of Electrical and Computer Engineering National University of Singapore117583Singapore

The terahertz(THz)antennas,which have features of small size,wide frequency bandwidth and high data rate,are important devices for transmitting and receiving THz electromagnetic waves in the emerging THz ***,most of THz antennas suffer from relatively high loss and low fabrication precision due to their small sizes in high frequency bands of THz ***,this paper presents a detailed overview of the most recent research on the performance improvement of THz ***,the development of THz antennas is briefly reviewed and the basic design ideas of THz antennas are ***,THz antennas are categorized as metallic antennas,dielectric antennas and new material *** that,the latest research progress in THz photoconductive antennas,THz horn antennas,THz lens antennas,THz microstrip antennas and THz on-chip antennas are *** particular,the practical difficulties for the development of THz antennas are discussed with promising *** addition,this paper also presents a short review of the process technology of THz ***,the vital challenges and the future research directions for THz antennas are presented.

关键词： sizes directions dielectric

In vivo spatial-spectral photoacoustic microscopy enabled by optical evanescent wave sensing

在线全文

学校读者我要写书评

暂无评论

Medicine in Novel Technology and Devices 2023年第2期18卷 258-266页

作者： Fan Yang Yushu Dong Changjun Min yejun he Siwei Zhu Hao Liu Wei Song Xiaocong Yuan Nanophotonics Research Center Shenzhen Key Laboratory of Micro-Scale Optical Information TechnologyInstitute of Microscale OptoelectronicsShenzhen UniversityShenzhen518060China Research Center for Humanoid Sensing Zhejiang LaboratoryHangzhou311100China College of Electronics and Information Engineering Shenzhen UniversityShenzhen518060China The Institute of Translational Medicine Tianjin Union Medical Center of Nankai UniversityTianjin300121China Tianjin Stomatological Hospital Hospital of Stomatology of Nankai UniversityNankaiTianjin300041PR China

In addition to offering morphological visualizations via capture of the spatial distributions of optical absorption,photoacoustic imaging technology can reveal abundant physical information about biological particles,including their orientation,density,and viscoelasticity,through analysis of the pressure transients in the spectral ***,the low-amplitude wideband photoacoustic signals of intrinsic microscopic optically-absorbing objects under the action of confined photoacoustic excitation power continue to hinder simultaneous photoacoustic structural imaging and spectroscopic analysis of the nonfluorescent chromophores in living biological tissues because of the inadequate responses to photoacoustic impulses observed in most photoacoustic imaging setups that include piezoelectric *** upon a recently-developed optical evanescent wave sensor that can respond to ultrasound with high sensitivity over a broad frequency range,we propose in vivo spatial-spectral photoacoustic microscopy for recovery of structural imaging in three dimensions and characterization of anatomical features in the acoustic frequency ***-free photoacoustic images of a living zebrafish are acquired in which spectroscopically-resolved differentiation of the microarchitecture is accessed,along with isometric micrometer-scale volumetric *** proposed imaging technology could potentially provide more comprehensive evaluations of the physiopathological status of living small animals.

关键词： Photoacoustic microscopy Optical evanescent wave sensing Spatial-spectral imaging In vivo imaging

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

一种全面屏智能手机天线设计

电波科学学报 2018年第4期33卷 422-428页

作者：何业军梁坤深圳大学信息工程学院深圳518000

提出一种适合在全面屏手机终端上使用,带宽为700～960MHz、1 710～2 170MHz、2 500～2 700MHz的手机天线.设计的手机仿真模型的长宽高尺寸为158mm×77mm×7.5mm,手机天线的长宽高尺寸为70mm×5mm×4mm,其天线效率分别为20%～35%(700～96... 详细信息

提出一种适合在全面屏手机终端上使用,带宽为700～960MHz、1 710～2 170MHz、2 500～2 700MHz的手机天线.设计的手机仿真模型的长宽高尺寸为158mm×77mm×7.5mm,手机天线的长宽高尺寸为70mm×5mm×4mm,其天线效率分别为20%～35%(700～960MHz)、20%～55%(1 710～2 170MHz)、25%～35%(2.5～2.7GHz).在目前全面屏天线净空区域3.5mm的情况下,天线的辐射效率能够满足设计要求.

关键词：全面屏手机天线多频段效率天线净空

A New Scheme of Bit-plane Coding in MPEG-4

在线全文

学校读者我要写书评

暂无评论

通讯和计算机（中英文版） 2005年第5期2卷 51-55页

作者： Feng Wang Guangxi Zhu Zhenming Zhang yejun he Dept. of Electronics and Information Engineering Huazhong University of Science ＆ Technology Wuhan 430074 China

基于Stackelberg博弈的双目标WOA频谱共享算法

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

通信学报 2020年第9期41卷 170-178页

作者：张力廖天何业军深圳大学电子与信息工程学院广东深圳518060

为解决复杂的频谱分配问题,引入具有较强并行计算能力的双目标鲸鱼优化算法(WOA),提出一种可以有效反映实际频谱需求的Stackelberg博弈,设计一种双目标WOA优化的分布式天线系统(DAS)频谱共享调度算法。仿真结果表明,从最优价格、用户收... 详细信息

为解决复杂的频谱分配问题,引入具有较强并行计算能力的双目标鲸鱼优化算法(WOA),提出一种可以有效反映实际频谱需求的Stackelberg博弈,设计一种双目标WOA优化的分布式天线系统(DAS)频谱共享调度算法。仿真结果表明,从最优价格、用户收益等多个指标进行性能对比,所提算法具有较好的频谱共享分配效果,能实现公平有效的频谱分配,为未来通信网络频谱共享模式提供了重要参考。

关键词：博弈理论双目标WOA Stackelberg博弈频谱共享

在线全文

学校读者我要写书评

暂无评论

3D金属打印天线技术研究综述

电波科学学报 2018年第3期33卷 266-278页

作者：陈亚玲何业军深圳大学信息工程学院深圳518000

近年来,随着通信用户量的迅速增加和通信设备市场的快速发展,数据速率高于10Gbit/s的高速通信系统要求多种功能集成在天线上,天线的制造要求趋于高精度、低成本和微型化.3D打印或增材制造(additive manufacturing,AM)是一种直接从数字... 详细信息

近年来,随着通信用户量的迅速增加和通信设备市场的快速发展,数据速率高于10Gbit/s的高速通信系统要求多种功能集成在天线上,天线的制造要求趋于高精度、低成本和微型化.3D打印或增材制造(additive manufacturing,AM)是一种直接从数字模型到零件制造的新兴产业技术,可在短时间内生产出高精度和复杂的天线零件,该技术已经成为了当前天线设计的研究热点.制造天线的AM技术主要有粉床熔合、材料挤压和材料喷射.文章首先简要介绍3D金属打印技术的基本原理、操作流程和分类,接着重点分析几种3D金属打印天线技术的研究成果,然后浅析3D金属打印天线技术的发展趋势,最后对3D金属打印天线技术做了总结.

关键词： 3D打印技术天线金属粉床熔合材料挤压材料喷射

Leaky-Wave Antennas for 5G/B5G Mobile Communication Systems:A Survey

在线全文

学校读者我要写书评

暂无评论

ZTE Communications 2020年第3期18卷 3-11,41页

作者： he yejun JIANG Jiachun ZHANG Long LI Wenting WONG Sai-Wai DENG Wei CHI Baoyong College of Electronics and Information Engineering Shenzhen UniversityShenzhen 518060China Institute of Microelectronics Tsinghua UniversityBeijing 100084China

Since leaky-wave antennas(LWAs)have the advantages of high directivity,low loss and structural simplicity,LWAs are very suitable for designing millimeter-wave(mmW)*** purpose of this paper is to review the latest research progress of LWAs for 5G/B5G mobile communication ***,the conventional classification and design methods of LWAs are introduced and the effects of the phase constant and attenuation constant on the radiation characteristics are *** two types of new LWAs for 5G/B5G mobile communication systems including broadband fixed-beam LWAs and frequencyfixed beam-scanning LWAs are ***,the challenges and future research directions of LWAs for 5G/B5G mobile communication systems are presented.

关键词： 5G/B5G beam-scanning frequency-fixed fixed-beam millimeter-wave(mmW) leaky-wave antenna(LWA)