无线工程与技术(英文) Pub Date : 2023-01-01 DOI: 10.4236/wet.2023.141001

R. Formato

引用次数: 0

Non-Uniform Pitch Helical Resonators for Dual-Passband Filter Design 用于双通带滤波器设计的非均匀螺距螺旋谐振器

无线工程与技术(英文) Pub Date : 2022-01-01 DOI: 10.4236/wet.2022.132002

Yahui Wu, R. Gajaweera, J. Everard

{"title":"Non-Uniform Pitch Helical Resonators for Dual-Passband Filter Design","authors":"Yahui Wu, R. Gajaweera, J. Everard","doi":"10.4236/wet.2022.132002","DOIUrl":"https://doi.org/10.4236/wet.2022.132002","url":null,"abstract":"This paper presents a study of a non-uniform pitch helical resonator (NPHR) structure and the coupling mechanisms to design dual-passband filters. The previous research analyzes NPHR as a type of step impedance resonator (SIR), however, it does not give analytical equations or prediction for the dual-resonance characteristics of the NPHR structure discussed in this paper. Consequently, a circuit model is proposed to analyze the dual-resonance characteristics of NPHRs. Analytical equations are derived, showing that the frequency ratio of a dual-band NPHR can be determined by the ratio of turns. EM simulation and experimental results have shown good agreement with the circuit analysis. The derived analytical equations from circuit model can be used for fast design of NPHRs. A step-width aperture is proposed to independently control the coupling coefficients at the each band of NPHRs. A third order dual-passband filter has been designed and fabricated. The filter has 3.3% and 3% fractional bandwidths at 789 MHz and 2402 MHz, respectively. The designed prototype filter shows that NPHRs can be utilized to realize compact filters with dual-band characteristics. The filter design can be extended from engineering perspective for application in wireless communication systems.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70840120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhancing Security in Correlated Nakagami-m Fading Cellular Network Using SC and SSC Diversity Combining 利用SC和SSC分集组合增强相关Nakagami-m衰落蜂窝网络的安全性

无线工程与技术(英文) Pub Date : 2022-01-01 DOI: 10.4236/wet.2022.131001

S. M. R. Ali, M. Sarkar

引用次数: 0

Design of Intelligent Water-Saving Irrigation System Based on Internet of Things 基于物联网的智能节水灌溉系统设计

无线工程与技术(英文) Pub Date : 2022-01-01 DOI: 10.4236/wet.2022.133003

Lingli Zhao

引用次数: 4

Six-Element Yagi Array Designs Using Central Force Optimization with Pseudo Random Negative Gravity 基于伪随机负重力中心力优化的六元八木阵列设计

无线工程与技术(英文) Pub Date : 2021-06-30 DOI: 10.4236/wet.2021.123003

R. Formato

{"title":"Six-Element Yagi Array Designs Using Central Force Optimization with Pseudo Random Negative Gravity","authors":"R. Formato","doi":"10.4236/wet.2021.123003","DOIUrl":"https://doi.org/10.4236/wet.2021.123003","url":null,"abstract":"A six-element Yagi-Uda array is optimally designed using Central Force Optimization (CFO) with a small amount of pseudo randomly injected negative gravity. CFO is a simple, deterministic metaheuristic analogizing gravitational kinematics (motion of masses under the influence of gravity). It has been very effective in addressing a wide range of antenna and other problems and normally employs only positive gravity. With positive gravity the six element CFO-designed Yagi array described here exhibits excellent performance with respect to the objectives of impedance bandwidth and forward gain. This paper addresses the question of what happens when a small amount of negative gravity is injected into the CFO algorithm. Does doing so have any effect, beneficial, negative or neutral? In this particular case negative gravity improves CFO’s exploration and creates a region of optimality containing many designs that perform about as well as or better than the array discovered with only positive gravity. Without some negative gravity these array configurations are overlooked. This Yagi-Uda array design example suggests that antennas optimized or designed using deterministic CFO may well benefit by including a small amount of negative gravity, and that the negative gravity approach merits further study.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48087827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Wi-Fi: WPA2 Security Vulnerability and Solutions Wi-Fi: WPA2安全漏洞及解决方案

无线工程与技术(英文) Pub Date : 2021-04-18 DOI: 10.4236/wet.2021.122002

Z. Najar, Roohe Naaz Mir

引用次数: 2

Wideband Reconfigurable Millimeter-Wave Linear Array Antenna Using Liquid Crystal for 5G Networks 用于5G网络的液晶宽带可重构毫米波线阵天线

无线工程与技术(英文) Pub Date : 2021-01-29 DOI: 10.4236/WET.2021.121001

A. Hassan, N. Fadlallah, M. Rammal, G. E. Nashef, E. Rachid

引用次数: 2

Central Force Optimization with Gravity < 0, Elitism, and Dynamic Threshold Optimization: An Antenna Application, 6-Element Yagi-Uda Arrays 重力< 0的中心力优化，精英主义和动态阈值优化:天线应用，六元Yagi-Uda阵列

无线工程与技术(英文) Pub Date : 2021-01-01 DOI: 10.4236/wet.2021.124004

R. Formato

{"title":"Central Force Optimization with Gravity < 0, Elitism, and Dynamic Threshold Optimization: An Antenna Application, 6-Element Yagi-Uda Arrays","authors":"R. Formato","doi":"10.4236/wet.2021.124004","DOIUrl":"https://doi.org/10.4236/wet.2021.124004","url":null,"abstract":"This paper investigates the effect of adding three extensions to Central Force Optimization when it is used as the Global Search and Optimization method for the design and optimization of 6-elementYagi-Uda arrays. Those extensions are Negative Gravity, Elitism, and Dynamic Threshold Optimization. The basic CFO heuristic does not include any of these, but adding them substantially improves the algorithm’s performance. This paper extends the work reported in a previous paper that considered only negative gravity and which showed a significant performance improvement over a range of optimized arrays. Still better results are obtained by adding to the mix Elitism and DTO. An overall improvement in best fitness of 19.16% is achieved by doing so. While the work reported here was limited to the design/optimization of 6element Yagis, the reasonable inference based on these data is that any antenna design/optimization problem, indeed any Global Search and Optimization problem, antenna or not, utilizing Central Force Optimization as the Global Search and Optimization engine will benefit by including all three extensions, probably substantially.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70839743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Over-the-Air Performance Evaluation in Indoor and Outdoor Multipath Propagation Channels of Antenna Diversity Systems inside Anechoic Chamber 消声室天线分集系统室内外多径传播信道的无线性能评价

无线工程与技术(英文) Pub Date : 2020-10-17 DOI: 10.4236/wet.2020.114004

A. Choumane, Ahmad El Sayed Ahmad, K. Khoder, Alaa Saleh

引用次数: 0

Multi-Band Antenna with Three Folded Monopoles for Mobile Communication Systems 用于移动通信系统的三折叠单极多频带天线

无线工程与技术(英文) Pub Date : 2020-07-16 DOI: 10.4236/wet.2020.113003

Ahmad El Sayed Ahmad, A. Choumane, J. Floch, P. Morgand

引用次数: 0

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