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Priyabrata Biswas Srija De Biplab Bag Debasree Chanda Sarkar Sushanta Biswas Partha Pratim Sarkar 《国际射频与微波计算机辅助工程杂志》2019,29(8)
Designing a high gain planar antenna on the low‐cost FR4 substrate is one of the major challenging tasks for the researchers. The omnidirectional radiation pattern is desired for 360° coverage. Both of these requirements have been addressed in this article. This article presents a dual band printed antenna designed on an FR4 substrate of 1.6 mm thickness. The proposed antenna operates in the ISM band of 2.4 and 5.8 GHz for the application of dual‐band WLAN/WIFI. The proposed antenna consists of a circular patch and ring‐shaped ground plane. The overall dimension of the antenna is 66 × 66 × 1.6 mm3. Excellent impedance matching and radiation efficiency for both the bands have been achieved. The proposed antenna shows omnidirectional radiation pattern at 2.4 GHz ISM band and nearly omnidirectional pattern along with high gain of 4.7 dBi at 5.8 GHz ISM band. 相似文献
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无线局域网技术是新世纪无线通信领域最有发展前景的技术之一。经过近几年的发展,无线局域技术已经日渐成熟,应用日趋广泛,较低的价格和成熟的产品推动着无线局域网技术从小范围应用进入主流应用。该文介绍了无线局域网技术的发展历程和各种无线网络的特点。着重介绍IEEE802．11n技术,包括IEEE802．11n发展现状、优点和应用发展前景。在今后的网络中,随着无线技术的不断发展,无线网络应用必将越来越广泛。 相似文献
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无线局域网技术是新世纪无线通信领域最有发展前景的技术之一。经过近几年的发展,无线局域技术已经日渐成熟,应用日趋广泛,较低的价格和成熟的产品推动着无线局域网技术从小范围应用进入主流应用。该文介绍了无线局域网技术的发展历程和各种无线网络的特点。着重介绍IEEE802.11n技术,包括IEEE802.11n发展现状、优点和应用发展前景。在今后的网络中,随着无线技术的不断发展,无线网络应用必将越来越广泛。 相似文献
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This letter investigates an integrated antenna configuration for WLAN/WiMAX applications. The proposed composite antenna configuration is simply the grouping of ring dielectric resonator along with reformed square‐shaped slot antenna. Three significant characteristics of proposed article are: (1) aperture act as magnetic dipole and excite HE11δ mode in ring dielectric resonator antenna; (2) reforming of square aperture generates orthogonal modes in ring DRA and creates CP in lower frequency band; (3) annular‐shaped Microstrip line along with reformed square aperture creates CP wave in upper frequency band. With the purpose of certifying the simulated outcomes, prototype of proposed structure is fabricated and tested. Good settlement is to be got between experimental and software generated outcome. Experimental outcomes show that the proposed radiating structure is operating over 2 frequency bands that is, 2.88‐3.72 and 5.4‐5.95 GHz. Measured 3‐dB axial ratio bandwidth in lower and upper frequency band is approximately 9.52% (3.0‐3.4 GHz) and 5.85% (5.64‐5.98 GHz), respectively. These outcomes indicate that the proposed composite antenna structure is appropriate for WLAN and WiMAX applications. 相似文献
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A. Oikonomou P. Demestichas K. Tsagkaris G. Koundourakis M. Theologou 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2005,9(2):128-142
BRAN/WLAN systems, e.g., HIPERLAN/2, IEEE 802.11a, etc., are seen as a promising solution for covering residential, business, transport, tourism, etc., environments, and generally areas of high demand, characterized as “hot spots”. This paper presents management functionality for augmenting the potential exploitation of one of these systems, HIPERLAN/2, by making feasible their (loose or tight) integration in a composite radio (CR) context. The approach will be the following. The first point will be to revisit the main features of a HIPERLAN/2 system. Next, the architecture of a general Service and Network Management System (SNMS), which has been developed for assisting wireless systems in their operation in a CR context, will be briefly presented. The next main point will be the presentation of the functionality of the SNMS component that is tailored to the managed HIPERLAN/2 technology and specifically to the configuration of the Power Control (PC) functionality. An algorithm for configuring the PC operation, based on a greedy algorithm and a neural network, will be presented. A relevant resource management problem, which should be efficiently solved for exploiting HIPERLAN/2 networks, will be addressed. Numerical results will be presented.
Acknowledgment This work was partially funded by the Commission of the European Communities, under the Fifth Framework Program, within the IST project MONASIDRE (IST-2000-26144: Management of Networks and Services in Diversified Radio Environment). 相似文献
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浅析无线局域网IEEE 802.11系列标准 总被引：1，自引：0，他引：1
赵贵昉 《网络安全技术与应用》2007,(5):94-95
本文主要阐述了无线局域网标准的发展历程和几个主要阶段,重点讨论了802．11g和802．11n两个标准以及其中所采用的关键技术OFDM和MIMO,最后总结了802．11n所具有的四个优势。 相似文献
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随着高速无线局域网物理层的制定,动态选择物理层传输模式的链路自适应被认为是一种有效提高系统吞吐量的方法。本文给出了两种基于IEEE802．11a DCF机制下的链路自适应算法,并对它们进行了理论分析与数值仿真,结论表明,基于MPDU的链路自适应算法优于基于MSDU的算法。在分析MPDU算法的基础上,我们给出了一种简单的通过查表来来选择最适合物理层传输模式的方法,并深入地讨论了此物理层传输模式表的建立过程。 相似文献
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Marc CiuranaAuthor Vitae Francisco Barceló-ArroyoAuthor VitaeIsrael Martín-EscalonaAuthor Vitae 《Computer Standards & Interfaces》2011,33(3):344-349
Time of Arrival (TOA) based techniques are expected to overcome performance limitations of existing WLAN positioning approaches. The upcoming IEEE 802.11v standard is expected to play a key role because it will include new specific mechanisms for TOA-based positioning with WLAN. This article analyzes some of these new capabilities and evaluates the performance enhancement that they can provide in practice. To this end, a comparative assessment between an existing WLAN TOA-based approach that uses IEEE 802.11 b/g and an analogous solution employing IEEE 802.11v is performed. 相似文献
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In this article, a novel dual‐band circularly polarized (CP) dielectric resonator antenna (DRA) for millimeter‐wave (MMW) band is presented. The rectangular dielectric resonator with layered truncated corners is excited by a microstrip‐coupled cross‐slot. CP radiations in the lower band are realized by utilizing two quasi‐TE111 modes operating at 21.7 GHz and 23.8 GHz, while CP radiations in the upper band are obtained by exciting a quasi‐TE113 mode at 28.2 GHz. The dual‐band DRA is fabricated and measured. Due to the higher order mode, the average gain of the DRA in the upper band is about 3 dB higher than that in the lower band. The measured impedance bandwidths (|S11| < ?10 dB) are 17.0% (20.5‐24.3 GHz) and 15.2% (26.1‐30.4 GHz), while the measured axial ratio (AR) bandwidths (AR < 3 dB) are 12.8% (21.2‐24.1 GHz) and 5% (27.4‐28.8 GHz). In addition, the peak gain values are 5 and 8 dBic. 相似文献
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Packet traces are important objects in networking, commonly used in a wide set of applications, including monitoring, troubleshooting, measurements, and validation, to cite a few. Many tools exist to produce and process such traces, but they are often too specific; using them as a basis for creating extended tools is then impractical. Some other tools are generic enough, but exhibit performance issues. This paper reports on our experience designing WiPal, a packet trace manipulation framework with a focus on IEEE 802.11. WiPal is designed for performance and re‐usability, while introducing several novel features compared to previous solutions. Besides presenting how WiPal's original design can benefit packet processing programs, we discuss a number of issues a program designer might encounter when writing packet trace processing software. An evaluation of WiPal shows that, albeit generic, it does not impact performance regarding execution speed. WiPal achieves performance levels observed only with specialized code and outperforms some well‐known packet processing programs. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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This article has proposed a circularly polarized dual‐band antenna with unidirectional pattern operating at the bandwidth frequencies of 920–925 MHz and 2.40–2.48 GHz for radiofrequency identification (RFID) readers. The proposed antenna structure is of a radiating patch with a single feeder and two pairs of plano convex and concave slots. This work has innovated and utilized the convex and concave slotting technique to generate the circular polarization. The simulated results showed that the dual‐band antenna is of circular polarization (CP) and unidirectional radiation pattern with the 3 dB axial ratio and the respective gains of 1.31 and 1.36 dBic for the experimental lower and upper bandwidth frequencies. An antenna prototype was subsequently fabricated and tests performed. The simulated and measured results are in good agreement, rendering the proposed dual‐band antenna with plano convex and concave slots suitably applicable to the ultrahigh frequency and microwave RFID readers. 相似文献
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提出了一种适用于GPS(1.575 GHz)和WLAN(2.45 GHz)工作的双频天线设计.该天线采用相互嵌套的内外方形贴片结构,其中内、外贴片分别对应高端谐振频率点、低端谐振频率点.在内贴片上开尺寸较大的矩形槽,降低高端谐振频率,从而实现了1.55倍的频率比.外贴片采用切角的方法实现右旋圆极化(RHCP),在内贴片对角位置切去两个大小不同的三角形微扰元,用以补偿开槽给内贴片上电流路径带来的不对称性,实现了高端谐振频率点处的阻抗匹配.该天线具有增益高、小型化、易于制造等优点. 相似文献
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A halved falcate‐shape dual‐broadband circularly polarized printed monopole antenna is proposed. To generate the equal amplitude orthogonal modes, two halved falcate‐shaped antenna are used. Also, to provide the 90° phase difference between the two modes, three stubs are used in the ground plane of the antenna. The proposed antenna provides 22.6 (1.36–1.72 GHz) and 44.4% (5.25–8.25 GHz) 3 dB axial ratio bandwidth over the lower and upper bands, respectively. By adjusting the parameters of the antenna, the lower and upper band center frequencies can be tuned individually. The proposed antenna is fabricated, and results are compared with those of the simulation. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2011. 相似文献
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Hari Shankar Singh Gaurav Kumar Pandey Pradutt Kumar Bharti Manoj Kumar Meshram 《国际射频与微波计算机辅助工程杂志》2015,25(6):510-521
A low profile triband compact multiple input multiple output (MIMO) antenna operating at WLAN, WiMAX, and HIPERLAN bands is presented. The proposed MIMO antenna consists of two planar inverted‐F antenna elements located at the top two corners of printed circuit board (PCB). Dimensions of each antenna elements are reduced substantially by employing a meandered line and folded patch structure so that it occupies a small volume of 9 × 8.8 × 5.4 mm3. The proposed antenna consists of three arms namely, Main arm, Side arm 1, and Side arm 2. Each individual arm resonates corresponding to the λ/4 electrical length. Characterization of the antenna is carried out in the mobile environment as well as in user proximity. In the presence of mobile environment which includes liquid crystal display (LCD), Battery, RF components, and plastic housing, the isolation as well as reflection coefficient parameters deteriorated. To avoid the aggravation of S‐parameters, two nonradiating folded shorting strips are connected between each antenna element and ground plane of PCB. This folded shorting strip not only improves the isolation between ports but also prevent the deterioration of reflection coefficient parameter. The total efficiency, envelope correlation coefficient, and multiplexing efficiency are studied in the user proximity. The optimized structure is fabricated and measured. The measured S‐parameters cover WLAN (2.46–2.6 GHz), WiMAX (3.37–3.75 GHz), and HIPERLAN (5.2–5.87 GHz) based on ?10 dB reflection coefficient and ?24 dB isolation is achieved between antenna ports. Good agreement is obtained between the simulated and measured results. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:510–521, 2015. 相似文献
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In this article, a polarization reconfigurable isosceles trapezoidal monopole antenna for the circular polarization (CP) is presented. A trapezoidal monopole and the ground plane are on the same side of the dielectric substrate. The monopole is excited by a reconfigurable T‐shaped 50 Ω microstrip feed line and reconfigurable vertical slots are incorporated in the ground plane to realize switchable wideband CP. For the different switching states of the p‐i‐n diodes, linear polarization, left‐handed and right handed CP can be achieved in the boresight direction (+z direction). The antenna prototype is fabricated and tested. The measured reflection coefficient bandwidth (|S11| < ?10 dB) is 31.2% (2.13 ‐ 2.91 GHz) and axial ratio bandwidth (axial ratio < 3 dB) is 22% (2.18 ‐ 2.72 GHz) for the CP. The measured reflection coefficient bandwidth is 18.56% (2.15 ‐ 2.59 GHz) for linear polarization. 相似文献
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A coplanar waveguide fed polarization reconfigurable monopole antenna is proposed in this letter. The proposed antenna consists of L‐shaped stubs placed on either side of a monopole, two p‐i‐n diodes and a slot in the ground plane. In the proposed antenna structure, the switching element is not directly connected to the feed line. Depending on the switching state of the p‐i‐n diodes, the antenna either radiates left/right circular polarization or linear polarization. To validate the proposed design, the antenna was fabricated and its performance was measured. Since the ground plane is electrically small, the effect of the cable and SMA connector on the performance of the antenna is also investigated. The measured impedance bandwidth is 66.78% (3.67 GHz to 7.35 GHz) and the axial ratio bandwidth is 13.62% (4.24‐4.86 GHz) for circular polarization and 23.61% (3.81‐4.83 GHz) impedance bandwidth for linear polarization. 相似文献
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A novel single‐fed dual‐band circular‐polarization (CP) reconfigurable liquid dielectric resonator antenna (LDRA) using 3D printing technology is proposed in this article. With the quasi‐TE111 and ‐TE113 modes of the rectangular LDRA excited, a dual‐band design is achieved. To realize the CP reconfigurability, a combined container, holding the fluidic dielectric (Ethyl acetate, ε r = 6.6), is fabricated by 3D printing technology. Therefore, the CP can be switched between two different states: (1) left hand CP (LHCP), when the right oblique container is full of the liquid solution; (2) right hand CP (RHCP), when the liquid solution is transferred into the left oblique one. Measured results demonstrate that the proposed antenna can achieve the CP reconfigurability in dual band, with the wide bandwidths (|S11| < ?10 dB and AR < 3 dB) of 10.4% (1.55‐1.72 GHz) and 9.7% (2.29‐2.52 GHz), which cover GPS and WLAN bands. 相似文献
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This paper presents a new approach to design dual‐band antenna with dual‐sense circularly polarized (CP) operation. A principle for CP radiation is the use of two orthogonal dipoles and properly choosing their lengths can produce either right‐hand CP (RHCP) or left‐hand CP (LHCP) operation. In the proposed structure, the lower frequency band at 2.4 GHz is designed with RHCP radiation and LHCP is the operating mode of the higher band at 3.5 GHz. For verification, an antenna prototype is fabricated and measured. Measured data indicate that good performances over the RHCP and LHCP bands can be obtained with usable bandwidths of 2.9% (2.36‐2.43 GHz) and 1.7% (3.48‐3.54 GHz). Along with this, it also observes good unidirectional radiation patterns and the measured broadside gains are around 7.7 and 7.4 dBic across these frequency ranges. 相似文献
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A single‐feed T‐type fractal boundary microstrip antenna is presented. It is established that a very good circular polarization is realizable with 3‐dB axial ratio bandwidth of 1.27% at the center frequency of 2446 MHz by changing the electrical length in two directions of the square patch by using T‐type fractal curve as boundary. Further it is shown that the surface area occupied by the antenna is reduced compared to the Euclidean shaped patch antenna without much degradation in gain of the antenna. Experimental results are compared with simulated results and a very good agreement is obtained. © 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2009. 相似文献