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radiation pattern analyses of circular aperture antenna to generate radio orbital angular momentum

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Journal of Central South University 2018年第6期25卷 1513-1523页

作者： LIN Cheng-long LIN Ming-tuan LIU Pei-guo TANG Xing College of Electronic Science National University of Defense TechnologyChangsha 410073China Army Agency Office of Nanjing Army Nanjing 210000China ~ Central South University Press and Springer-Verlag GmbH Germanypart of Springer Nature 2018

Circular aperture antenna recently has been regarded as a nature source to generate high power radio orbital angular momentum （OAM） in millimeter （mm） wave; however, the radiation pattern was not investigated. Theoretical derivation of radiation pattern of circular aperture OAM antenna is conducted to evaluate the performance. Extensive simulations verify the validity of the theoretical result. Furthermore, performance of such antenna excited by orthogonal TE and TM modes is compared, which shows the potential application for TEgl mode to create pure OAM g-1 mode in a practical system, providing guidance for generation of twisted radio waves in mm-wave bands.

关键词： orbital angular momentum (OAM) twisted radio wave millimeter-wave circular aperture antenna radiation pattern TE mode TM mode

Reconstruction of Antenna radiation pattern Based on Compressed Sensing

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Journal of Shanghai Jiaotong university(Science) 2020年第6期25卷 790-794页

作者： ZHANG Haoping JIANG Yilin LI Xiaoyu College of Information and Cormmunication Engineering Harbin Engineering UniversityHarbin 150001China

The measurement of the far-field radiation pattern is an important factor in describing the character-istics of the *** measurement process is time consuming and ***,this paper proposes a novel method to reduce the number of samples required for radiation pattern measurement by adopting com-pressed sensing *** method reconstructs the radiation pattern from data measured by a few sensors,and the positions of these sensors are generated via the *** results demonstrate that the proposed algorithm can effectively reconstruct the complete radiation pattern by using the 50%samples.

关键词： far-field radiation pattern compressed sensing m-sequence

Feedline Separation for Independent Control of Simultaneously Different Tx/Rx radiation patterns

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Computers, Materials & Continua 2022年第8期72卷 2221-2241页

作者： Akarachai Inthanil Monthippa Uthansakul Peerapong Uthansakul School of Telecommunication Engineering Suranaree University of TechnologyNakhon Ratchasima30000Thailand

The shortcoming of Wi-Fi networks is that one user can access the router at a *** drawback limits the system throughput and *** paper proposes a concept of Simultaneously Different Tx/Rx(SDTR)radiation patterns with only one antenna set at the ***,these two patterns have to be simultaneously operated at the same time so that the system delay can be *** omni-directional pattern is employed at router for receiving mode so that the router can sense carrier signal from all *** the same time,the router launches a directional beam pointed to another user.A proposed circuit allows these two modes to be able to operate the same *** evaluate the SDTR concept,a prototype is constructed for testing in real circumstance comparing to computer *** a result,the SDTR concept can improve the system throughput while decreasing the system delay comparing to conventional system.

关键词： Wireless networks wi-fi throughput delay radiation pattern

Seismic moment tensor representations and radiation patterns in unbounded media with elipsoidal cavities driven by low frequency pressure

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Acta Seismologica Sinica(English Edition) 1997年第5期10卷 1-12页

作者：靳平徐果明楼为涛

Seismic waves generated in elastic media by ellipsoidal cavities driven by low frequency pressure can be solved by Eshelby′s method. In this paper we prove that this method, originally presented for elastostatic ellipsoidal inclusion problems, can also be applied to dynamic problems on the assumption that wavelengths are much longer than the dimensions of cavities. Comparison between the approximate solution for spherical cavities and its relevant precise solution shows that this method may be used for radii of cavities smaller than 100 m and for frequencies below 10 Hz. By this approach we show that, for low frequency seismic waves in the far field an explosive load on an ellipsoidal cavity can be equivalent to three dipoles oriented along the principal axes of that cavity. Seismic radiation patterns are given analytically and results thus obtained show that an explosion detonated in an ellipsoidal cavity may radiate significant S waves.

关键词： ellipsoidal cavity explosive source seismic moment radiation pattern

A Generalized Array Factor for Time-Modulated Hexagonal Based Antenna Array Geometry With Novel Trapezoidal Switching

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IEEE/CAA Journal of Automatica Sinica 2024年第9期11卷 1967-1972页

作者： Gopi Ram Department of Electronics and Communication Engineering National Institute of TechnologyWarangal 506004India

The concept of the time-modulated array has been emerging as an alternative to the complex phase shifters,which lowers the cost of the array feeding network due to the utilization of radio frequency(RF)*** various forms of hexagonal antenna array geometries can be used for applications like surveillance tracking in phased array radar and wireless communication *** work proposes the generalized array factor(AF)for the hexagonal antenna array geometry based on time *** time modulation in generalized hexagonal geometry can maintain the fixed static amplitude excitation,giving more flexibility over ***,a novel trapezoidal switching function is also proposed and applied to the generalized array factor to enable future researchers to use this array factor in the field of advancement to observe how switching schemes like trapezoidal and rectangular affect the array pattern's side lobe level(SLL).The generalized equation can be utilized for the analysis and synthesis of radiation characteristics of the time-modulated hexagonal array(TMHA),time-modulated concentric hexagonal array(TMCHA),time-modulated hexagonal cylindrical array(TMHCA),and time-modulated hexagonal concentric cylindrical array(TMHCCA).The numerical result illustrates the generation of AF of time-modulated hexagonal structures and also shows that the trapezoidal switching sequence outperforms the rectangular switch using the cat swarm optimization(CSO)approach.

关键词： Hexagonal array geometry radiation pattern time-modulation trapezoidal pulse

Beamforming Performance Analysis of Millimeter-Wave 5G Wireless Networks

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Computers, Materials & Continua 2022年第3期70卷 5383-5397页

作者： Omar A.Saraereh Ashraf Ali Deparment of Electrical Engineering Engineering FacultyThe Hashemite UniversityZarqa13133Jordan

With the rapid growth in the number of mobile devices and user connectivity,the demand for higher system capacity and improved qualityof-service is *** the demand for high-speed wireless communication grows,numerous modulation techniques in the frequency,temporal,and spatial domains,such as orthogonal frequency division multiplexing(OFDM),time division multiple access(TDMA),space division multiple access(SDMA),and multiple-input multiple-output(MIMO),are being *** with those approaches,electromagnetic waves’orbital angular momentum(OAM)is attracting attention because it has the potential to boost the wireless communication *** electromagnetic radiation can be described by a sum of Eigen functions with unique eigenvalues,as is well *** order to address such issues,the millimeter-wave(mmWave)communication is proposed which is considered as one of the potential technology for 5G wireless *** intrinsic feature of all electromagnetic waves is *** OAM beams’unique qualities have led to a slew of new *** OAM generators,on the other hand,have gotten very little attention,especially in the mmWave frequency *** use of OAM in conjunction with mmWave can reduce the beam power loss,enhance the received signal quality,and hence increase the *** transmitter and receiver antennas must be coaxial and parallel to achieve precise mode *** proposed mmWave integrated with OAM system model is discussed in this *** channel model is created using the channel transition *** simulation results demonstrate that the proposed system model is a good way to boost the system capacity.

关键词： Antennas beamforming radiation pattern mmwave optimization

A Compact Rhombus Shaped Antenna with Extended Stubs for Ultra-Wideband Applications

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Computers, Materials & Continua 2022年第11期73卷 2637-2650页

作者： Syed Misbah un Noor Muhammad Amir Khan Shahid Khan NZ Jhanjhi Mamoona Humayun Hesham A.Alhumyan Department of Electrical Engineering IIC University of TechnologyPhnom PenhCambodia Department of Computer Science COMSATS University IslamabadAbbottabad Campus22060Pakistan Department of Electrical and Computer Engineering COMSATS University IslamabadAbbottabad Campus22060Pakistan School of Computer Science SCSTaylor’s UniversitySubang Jaya47500SelangorMalaysia 5Center for Smart Society 0 CSS5 Faculty of Innovation and TechnologyTaylor’s UniversitySubang Jaya47500Malaysia Department of Information Systems College of Computer and Information SciencesJouf UniversityAl-JoufKSA

Ultra-wideband(UWB)is highly preferred for short distance *** a result of this significance,this project targets the design of a compact UWB *** paper describes a printed UWB rhombusshaped antenna with a partial ground *** achieve wideband response,two stubs and a notch are incorporated at both sides of the rhombus design and ground plane *** excite the antenna,a simple microstrip feed line is *** suggested antenna is built on a 1.6 mm thick FR4 *** proposed design is very compact with overall electrical size of 0.18λ×0.25λ(14×18 mm2).The rhombus shaped antenna covers frequency ranging from 3.5 to 11 GHz with 7.5 GHz impedance *** proposed design simulated and measured bandwidths are 83.33%and 80%,*** pattern in terms of E-field and H-field are discussed at 4,5.5 and 10 GHz *** proposed design has 65%radiation efficiency and 1.5 dBi peak *** proposed design is simulated in CST(Computer Simulation Technology)simulator and the simulated design is fabricated for the measured *** simulated and measured findings are in close *** obtained results confirm the application of the proposed design for the ultra-wide band applications.

关键词： Ultra-wideband impedance bandwidth radiation pattern CST electrical size

OPTIMIZATION ON ANTENNA pattern OF SPACEBORNE SAR WITH IMPROVED NSGA-Ⅱ

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Journal of Electronics(China) 2009年第4期26卷 443-447页

作者： Xiao Jiang Wang Xiaoqing Zhu Minhui Xiao Liu National Key Laboratory of Microwave Imaging Technology Beijing 100190 China Institute of Electronics Chinese Academy of Sciences Beijing 100190 China

Optimization of antenna array pattern used in a spaceborne Synthetic Aperture Radar (SAR) system is considered in this study. A robust evolutionary algorithm, Non-dominated Sorting Genetic Algorithms (the improved NSGA-Ⅱ), is applied on a spaceborne SAR antenna pattern design. The system consists of two objective functions with two constraints. Pareto fronts are generated as a result of multi-objective optimization. After being validated by a test problem ZDT4, the algorithms are used to synthesize spaceborne SAR antenna radiation pattern. The good results with low Ambi- guity-to-Signal Ratio (ASR) and high directivity are obtained in the paper.

关键词： Synthetic Aperture Radar (SAR) radiation pattern Improved Non-dominated Sorting Genetic Algorithms (NSGA)-Ⅱ Ambiguity-to-Signal Ratio (ASR)

Analysis of the Spherical-Circular Patch Antenna

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The Journal of China Universities of Posts and Telecommunications 1996年第2期3卷 9-13,21页

作者： Liao Chengen and Liu Qing(Xi’an Institute of Posts and Telecommunications, Xi’an, 710061, P. R. China)Yu Chunyang(Xi’an Jiaotong University, Xi’an 710049, P. R. China)

A comprehensive analysis of a thin spherical-circular micros trip patch antenna which includes resonant frequencies and radiation patterns are presented using cavity-mode theory in this paper. Numerical and graphical results are given to illustrate the effects of curvature and taper-angle of the patch on the characteristics of the TM01 and TM11 modes.

关键词： s: spherical-circular patch antenna resonant frequency radiation pattern