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WLAN

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Engineering87%

Terms modified by WLAN

  • wlan access point
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  • wlan application
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    Selected Abstracts

    Access network discovery and selection in the evolved 3GPP multi-access system architecture

    EUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 6 2010
    Joachim Sachs
    The system architecture evolution (SAE) of mobile networks specified in 3GPP release 8 comprises an evolved packet core (EPC) network to which different types of access networks can be connected. Inter-system mobility management enables users to change the access network while maintaining ongoing data sessions. One important functionality in a 3GPP system is how a mobile terminal discovers and selects available access networks. In this paper we describe the access network discovery and selection functionality used in 3GPP release 8; we explain the differences of the methods applied for 3GPP access networks (GERAN, UTRAN, E-UTRAN), for fixed or wireless non-3GPP access networks (e.g. WLAN, WiMAX), as well as the optimisation used for CDMA2000 access networks. Copyright © 2010 John Wiley & Sons, Ltd. [source]

    A network-centric approach for access and interface selection in heterogeneous wireless environments

    INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 5 2008
    George Koundourakis
    Abstract In this paper, we introduce a network-based approach for access and interface selection (AIS) in the context of resource management in heterogeneous wireless environments (UMTS, WLAN and DVB-T). We focus on the optimization of resource utilization, while ensuring acceptable quality of service (QoS) provision to the end users. Our objective is to optimally manage the overall system resources and minimize the possibility of QoS handovers (non-mobility handovers). The adopted architecture applies to typical heterogeneous environments and network entities (Access Routers) are enhanced with extra functionalities. We propose an AIS algorithm that exploits the multihoming concept and globally manages network resources at both radio access and IP backbone networks. The algorithm can estimate near-optimal solutions in real time and we also introduce a novel triggering policy. We present simulation results of typical scenarios that demonstrate the advantages of our approach. System performance metrics, derived from the simulations, show minimum degradations in high load and congestion situations. Copyright © 2007 John Wiley & Sons, Ltd. [source]

    Enhancing multimedia streaming over existing wireless LAN technology using the Unified Link Layer API

    INTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 5 2007
    Tim Farnham
    This paper examines how multimedia streaming scenarios can be enhanced by cross-layer interaction, and in particular link performance information and configuration options provided by the recently developed Unified Link Layer API (ULLA). It provides results of an experimental implementation developed for this purpose in a wireless LAN (WLAN) environment. Multimedia streaming is an application that is gaining in popularity for mobile devices and in particular mobile Internet-based content broadcasting is rapidly emerging as a key feature on mobile devices. In these scenarios, the wireless link (last hop) is normally the performance bottleneck due to the dynamic and limited capacity of the wireless medium. The use of ULLA in this context can provide the ability to tailor the video transmission to the wireless link performance and also to configure the links in response to performance problems or environmental changes. For this purpose the focus of multimedia streaming has been on WLAN link technology and dynamic adaptation (i.e., dynamic channel selection and video transcoding) using a dynamic resource reservation overlay protocol. Copyright © 2007 John Wiley & Sons, Ltd. [source]

    Enabling location-based services in wireless LAN hotspots

    INTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 3 2005
    Yen-Cheng Chen
    The wide deployment of IEEE 802.11 Wireless LAN (WLAN) makes possible application services developed in WLAN hotspots. Owing to the small cell size in WLAN hotspots, it is practical to develop location-based services with the awareness of the WLAN access points (APs) that mobile devices currently access. In this paper, we propose an effective location determination technique using the inherent SNMP support in WLAN APs. It is shown that the current location of a mobile device can be determined from the SNMP traps sent by APs. Since the SNMP-based approach doesn't need any particular software or hardware in mobile devices, location-based services can be widely deployed, especially in public WLAN hotspots. To further enable location-based services through the WWW, this paper also considers the location determination of a mobile device from its IP address, retrieved in a WWW environment. In addition, we propose a web service framework for location-based services in WLAN hotspots. Thus, location-based services can be developed in a standard way.,Copyright © 2005 John Wiley & Sons, Ltd. [source]

    Roaming and service management in public wireless networks using an innovative policy management architecture

    INTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 2 2005
    Idir Fodil
    Nowadays, public wireless local area networks (WLANs), commonly called hotspots, are being largely deployed by WISPs (Wireless Internet Service Providers) as a means of offering ubiquitous Internet access to their customers. Although a substantial number of solutions have been proposed to improve security, mobility and quality of service on the wireless area, access network management which is mandatory remains a very significant concern. This paper describes RSM-WISP, a new management architecture designed for WISPs to facilitate the implementation and management of the services they offer at the access side of the WLAN, and to manage roaming contracts between WISPs. Our architecture is based upon the policy-based management principles as introduced by the IETF, combined with more intelligence at the network edge. RSM-WISP adopts an architecture that is composed of two elements: a WISP management center (MC) that deploys policies and monitors all the WLANs, and a programmable access router (CPE) located in each WLAN. The CPE ensures service enforcement, service differentiation (access to different service levels) and guarantee, user access management, and dynamic WLAN adaptation according to the user's SLA (service level agreement). It also permits automatic service updates according to the user's requirements. Concerning roaming management, this is achieved on the CPE through multiple service provider support capabilities. This approach provides WISPs with a simple, flexible and scalable solution that allows easy service deployment and management at the access. This management architecture has been implemented, tested and validated on the 6WINDGate routers.,Copyright © 2005 John Wiley & Sons, Ltd. [source]

    AAA architecture for mobile IPv6 based on WLAN

    INTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 5 2004
    R. C. Wang
    Mobility support for Internet devices is quite important for consumer electronics. The number of the hand-held devices is growing quickly. However, there are not enough IP addresses for the number of the rapidly growing devices in the All-IP generation. Internet Protocol version 6 (IPv6) was therefore adopted to solve these problems. Our purposed structure is based on IEEE 802.11. However, IEEE 802.11 has a serious security drawback. Further, from the Internet Service Providers' point of view, accounting is a potential problem. A mechanism combining Mobile IPv6 and AAA based on IEEE 802.11 to overcome these problems is essential. Both Internet Protocol version 4 (IPv4) and IPv6 support IP security (IPsec) when data packets are exchanged across the IP network. IPsec operates at the IP layer. It can support system authentication and authorization, However, it lacks a system accounting function. Therefore ISPs cannot establish correct billing for their services. This is the reason why we chose to combine the wireless network and AAA functions. In this paper, the AAA mechanism is used to protect security, with the architecture having authentication, authorization, and accounting functions. We will discuss the benefits of AAA and state the reason why we choose to combine AAA with the mobility architecture.,Copyright © 2004 John Wiley & Sons, Ltd. [source]

    Modeling and optimization of cylindrical antennas using the mode-expansion method and genetic algorithms

    INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 6 2005
    Dawei Shen
    Abstract For monopole antennas with cylindrically symmetric structures, a mode-expansion method is highly time efficient, which is a realistic approach for integrating function-optimization tools, such as genetic algorithms (GAs), in order to extract the best bandwidth property. In this article, a mode-expansion method is used to simulate the impedance characteristics of the cylindrical antennas. As examples, two new types of monopole antennas are presented, one of which possesses a two-step top-hat structure while the other has an annulus around the stem. After the modeling scheme is examined for convergence and data validity, the associated optimization problem, with dimensions as decision variables, structural limitations as linear constraints, and desired bandwidth performance as an objective function, is solved using GAs. The effects of the geometric parameters on the impedance characteristics are investigated in order to demonstrate the optimality of the calculated solutions. Two optimized practical antennas are designed based on our numerical studies. One has a broad bandwidth of 3 GHz while the other shows a dual-band property, which can satisfy the bandwidth requirements for both Bluetooth (2.45-GHz band) and WLAN (5-GHz band) systems. © 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2005. [source]

    A 3-V variable-gain amplifier in Si/SiGe BiCMOS technology for 5-GHz WLAN applications

    INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 5 2005
    F. Alimenti
    Abstract A variable-gain class-A amplifier for 5-GHz wireless local area networks (WLAN) applications is developed using commercial 0.35-,m Si/SiGe BiCMOS technology. The amplifier is based on a cascode differential pair and is fully integrated with input and output matching networks. The design starts with application of the Cripps' method and it is further refined by nonlinear harmonic-balance simulations. These simulations are in good agreement with the measurements carried out at wafer level on a realized prototype. © 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE 15, 2005. [source]

    Compact dual-band multiple input multiple output antenna with high isolation performance

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2010
    Insu Yeom
    Abstract A compact dual-band (WLAN 11b; 2.4 GHz , 2.5 GHz, 11a; 5.15 GHz , 5.825 GHz) 2-channel Multiple Input Multiple Output (MIMO) antenna for portable media player (PMP) applications is presented. The proposed antenna is composed of a planar inverted F-shape antenna (PIFA) operating at 2 GHz band and a loop antenna operating at 5-GHz band. The antenna made up of the composite loop and PIFA antenna (CLPA) with connecting line face to the feed point and is orthogonally arranged at the edge of the ground plane for reducing mutual coupling. The antenna shows polarization and pattern diversities with excellent isolation characteristics. The two antennas were connected with each other in the bottom side to improve the isolation at 5-GHz band. The proposed antenna has a sufficient gain in WLAN service band and is compact sized for the PMP applications. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2808,2811, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25614 [source]

    Novel planar triple band monopole antenna for WiMAX/WLAN applications

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2010
    Hsien-Wen Liu
    Abstract A coplanar waveguide (CPW)-fed planar monopole antenna with triple band operation for worldwide interoperability for microwave access (WiMAX) and wireless local area network (WLAN) applications is presented. The antenna, which occupies a small size of 25 (L) × 25 (W) × 0.8 (H) mm3, is simply composed of a pentagonal radiating patch with two bent slots. By carefully selecting the positions and lengths of these slots, good dual stopband rejection characteristic of the antenna can be obtained, so that three operating bands covering 2.14,2.85, 3.29,4.08, and 5.02,6.09 GHz can be achieved. The measured results also demonstrate that the proposed antenna has good omnidirectional radiation patterns with appreciable gain across the operating bands, and is thus suitable to be integrated within the portable devices for WiMAX/WLAN applications. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2405,2408, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25497 [source]

    Dual band-notched ultra-wideband printed antenna with two different types of slots

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 9 2010
    Jun-Bo Jiang
    Abstract A compact wideband printed antenna with dual band-notched characteristics for wireless local area network (WLAN) (2.4 GHz/5.8 GHz) is introduced. It is demonstrated that dual band rejection characteristics at 2.4 and 5.8 GHz with desired bandwidths can be obtained by using two different types of slots, one is a folded stripline slot on the radiation patch, and the other is a pair of inverted-L-shaped slot on the ground. The proposed antenna operates over 2.2,11 GHz for VSWR <2, while providing a band-stop function in the frequency bands of 2.3,2.9 GHz and 5.5,6.3 GHz. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1930,1933, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25411 [source]

    A coupling-fed multiband antenna for WLAN/WiMAX applications

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 6 2010
    Shaoli Zuo
    Abstract A coupling-fed printed monopole antenna applied to wireless local area network/worldwide interoperability for microwave access (WLAN/WiMAX) applications is proposed. By using a pair of branch-shaped strips, which are symmetrical with a gradual changing strip, the proposed antenna exhibits multiband performance to meet the requirements of WLAN in the 2.4/5.2/5.8 GHz bands and WiMAX in the 2.5/3.5/5.5 GHz bands. The proposed antenna has good omnidirectional radiation characteristic owing to its symmetric structure and achieves gains to be 2.44, 3.74, 3.3, and 2.02 dBi at 2.4, 3.5, 5.2, and 5.8 GHz, respectively. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1283,1286, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25197 [source]

    A dual-band split-ring monopole antenna for WLAN applications

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2009
    Siddik Cumhur Basaran
    Abstract In this article, a novel dual-band microstrip monopole antenna based on split-ring elements is proposed for WLAN (2.4/5 GHz) applications. The antenna fed by a two-stage microstrip line has fairly small dimensions and provides 7.5 and 25.5% impedance bandwidth performance at the respective bands. Also, the antenna exhibits almost uniform radiation patterns at each frequency band. The measurement results of the fabricated antenna are in good agreement with the simulations. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2685,2688, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24708 [source]

    A compact triple-band antenna design for UMTS, WLAN and WiMAX applications

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 9 2009
    Jhin-Fang Huang
    Abstract A compact triple-band planar antenna applied to UMTS, WiFi and WiMAX applications is proposed. The proposed antenna provides three wide frequency bands, which are 1744,2759 MHz, 3271,4126 MHz and 4718,5908 MHz, realized in a commercial FR4 printed- circuit board (PCB) with a permittivity of 4.4 and thickness of 0.6 mm. Both simulation and measurement are pretty matched and indicate that the proposed antenna achieves gains to be 3.5, 3.0, and 2.5 dBi at 2.4, 3.5, and 5.2 GHz, respectively. The antenna dimension is 52.8 × 31.2 mm2, smaller than presently published antennas discussed in comparison table. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2207,2212, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24522 [source]

    An internal multiband antenna for WLAN and WWAN applications

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 8 2009
    Chien-Wen Chiu
    Abstract In this letter, we propose a novel multiband antenna which can be integrated into a laptop computer for WLAN and WWAN applications. The antenna, evolved from a dual-band inverted-F antenna, is mounted on the top-edge of a vertical ground plane of LCD panel. By adding four parasitic resonators which are short-circuited quarter-wavelength elements, the antenna can achieve wideband performance to cover GSM850/GSM900/DCS/PCS/UMTS and 802.11a/b/g. A simulation was performed by HFSS to optimally design the antenna, and then a practical structure was also fabricated to verify the simulation results. The measured antenna parameters as well as the radiation efficiency are presented to validate the proposed antenna. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1803,1807, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24501 [source]

    Compact slot antenna for 2.4 GHz/UWB with dual band-notched characteristic

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 8 2009
    Feng-Tao Zha
    Abstract A novel compact microstrip slot antenna for 2.4,2.5 GHz (WLAN) band and ultra-wideband is proposed and fabricated. Two single ring split resonators are etched in the feed line to obtain dual band-notched function in the 5 GHz WLAN band and ITU 8025,8400 MHz band, respectively. The entire antenna only occupies a volume of 33 mm × 35.5 mm × 1 mm. The proposed antenna is analyzed both numerically and experimentally. The measured results and simulated results reach good agreements. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1859,1862, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24475 [source]

    Design of dual-band antenna with U-shaped open stub for WLAN/UWB applications

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2009
    Jung N. Lee
    Abstract In this article, we have proposed a dual-band antenna with U-shaped open stub for wideband local area network (WLAN)/ultra wideband (UWB) applications. The designed dual-band antenna consists of two semicircle radiating patches, a rectangular slot separating the two semicircles, one step for impedance matching, and coplanar waveguide (CPW) feeding. Two kinds of prototypes (CPW-fed UWB antenna and the dual-band antenna with U-shaped open stub) are fabricated and measured. Parametric studies and radiation characteristics for the two antennas are presented. The designed antenna has the figure-of-eight radiation pattern, wide bandwidth, and negligible dispersion over the operating frequency band. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 284,289, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24033 [source]

    Lattice-type balun with enhanced phase characteristic based on organic system on a package technology

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2009
    Jong C. Park
    Abstract In this article, lattice-type LC balanced-to-unbalanced (balun) embedded into a multilayered organic package substrate have been designed, fabricated, and characterized for low cost and small size WLAN and Bluetooth applications. To minimize the phase error of the embedded baluns, LC resonator was utilized instead of shunt capacitor used at conventional lattice-type balun, furthermore, the quality factors and packaging efficiencies of embedded inductors are maximized by using vertically stacked circular geometry. It has the insertion loss of 0.7 dB, return loss of 21 dB, phase imbalance of 5°, and frequency band width ranged from 2.3 to 2.55 GHz. The fabricated balun was significantly reduced in size and volume by using the vertically stacked spiral inductors and MIM capacitors with BTO high DK film. It has a size of 2.7 ×2.5 ×0.66 mm (height). It is promising for various RF system on a package (SOP) products with multi functionalities, small size, and low cost. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 399,402, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24041 [source]

    Compact multiband slotted antenna for wireless communication applications

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2009
    Yi-Chieh Lee
    Abstract New design of a compact antenna with slotted structure for multioperating bands of wireless communication systems is presented. By using compact configuration and slot designs on printed circuit board, the proposed antenna has the multiband measured operations for covering the 2.4-GHz WLAN (2.4,2.484 GHz), the WiMAX (IEEE 802.16e in the Taiwan: 2.5,2.69/3.5,3.65 GHz), and the 5-GHz WLAN (5.15,5.35/5.725,5.825 GHz) bands. Several properties of the proposed compact antenna for multiband operation such as impedance bandwidth, radiation pattern, and measured gain have been numerically and experimentally investigated. © 2008 Wiley Periodcals, Inc. Microwave Opt Technol Lett 51: 502,503, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24094 [source]

    Seven-band folded-loop chip antenna for WWAN/WLAN/WiMAX operation in the mobile phone

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2009
    Ming-Ren Hsu
    Abstract A chip antenna formed by using an FR4 chip base and a folded-loop metal pattern embedded therein for internal mobile phone antenna application is presented. The folded-loop metal pattern is embedded in two different layers inside the FR4 chip base to achieve a compact structure, and a coupling gap is introduced to successfully excite two wide operating bands at about 900 and 2000 MHz to cover GSM850/900/1800/1900/UMTS, 2.4-GHz WLAN, and 2.5-GHz WiMAX operations; that is, a seven-band internal mobile phone antenna for covering WWAN/WLAN/WiMAX operation is obtained. The proposed chip antenna also occupies a small volume of 4 × 5 × 40 mm3 (0.8 cm3) and shows a low profile of 5 mm when mounted on the system circuit board of the mobile phone, making it suitable for thin mobile phone applications. The proposed chip antenna is studied and tested. The SAR effect of the antenna is also analyzed in the study. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 543,549, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24063 [source]

    Wideband cylindrical monopole antenna for multiband wireless applications

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 1 2009
    Joong-Chang Chun
    Abstract A wideband cylindrical monopole antenna is presented for multiple band applications. Wideband property of the proposed antenna is achieved by the additional resonance from a stepped base part and a convex ground plane. The measured ,10 dB impedance bandwidths are 1.74,3.06 and 5.59,10.62 GHz, which can cover various kinds of wireless services such as PCS (1.75,1.87 GHz), IMT-2000 (1.92,2.17 GHz), WiBro (2.3,2.39 GHz), WLAN (2.412,2.483 GHz, 5.725,5.825 GHz), DMB (2.63,2.655 GHz), and high-band UWB in Korea (7.2,10.2 GHz). © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 15,17, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23981 [source]

    Ultrathin planar inverted-F antenna for multistandard handsets

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2008
    Rashid A. Bhatti
    Abstract A compact multiband internal antenna has been proposed for multistandard personal communication handsets. The antenna simultaneously covers various frequency bands such as GSM, DCS, PCS, UMTS, WiBro, Bluetooth, S-DMB, and WLAN. Total volume of the antenna is 0.78 cm3 (2.6 cm × 1.5 cm × 0.2 cm) that makes it attractive for multiband slim handsets. Measured performances of the prototype antenna are acceptable at all the targeted frequency bands. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2894,2897, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23808 [source]

    Design of dual-band bandpass filter using diverse quarter-wavelength resonators for GPS/WLAN applications

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2008
    Hung-Wei Wu
    Abstract The novel compact dual-band bandpass filter (BPF) by using diverse quarter-wavelength (,/4) resonators for global position system (GPS)/wireless local area network (WLAN) applications is proposed for the first time. The use of two interdigital-like ,/4 resonators of the proposed BPF effectively provides the responses for GPS/WLAN at 1.575/5.7 GHz by properly arranging the ,/4 SIRs. Full-wave simulator IE3D is used to design the proposed BPF. Good agreement with responses of electromagnetic (EM) simulation and measurement is compared. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2694,2696, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23716 [source]

    Compact band-notched ultra-wideband printed antenna

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2007
    Yi Ding
    Abstract A novel and compact ultra-wideband (UWB) printed monopole antenna with extended band-notched designs is presented. The antenna with a total size of 20 mm × 35 mm operates in a band from 3 to over 11 GHz (VSWR , 2), and shows omnidirectional radiation with a low cross-polarization in the range of the operated band. Measured results indicate that the antenna presents a notched-band from 5.1 to 6 GHz for VSWR , 3:1, which covers the wireless local area network (WLAN) band. The notched-band is produced by an embedded resonant cell (ERC). Experimental results show that the band-notched function can be controlled by adjusting the length of the ERC and area of the slot. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2686,2689, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22842 [source]

    Dual-band monopole antenna excited by a capacitive coupling feed for WLAN applications

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2007
    Chih-Yu Huang
    Abstract A printed dual-band T-shaped monopole antenna with a shorted strip fed by a coupling microstrip line for wireless communication in the wireless local-area network (WLAN) band is studied. The proposed antenna can provide two separate impedance bandwidths of 101 MHz (about 4.1% centered at 2.45 GHz) and 1490 MHz (about 27% centered at 5.5 GHz), making it easier to cover the required bandwidths for WLAN operation in the 2.45 GHz band (about 3.4% bandwidth required) and 5.2/5.8 GHz bands (about 13% bandwidth required). We can easily find the enhancement of impedance bandwidth by using capacitive coupling feed. Details of the proposed antenna design and experimental results are presented and discussed. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1135,1138, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI.10.1002/mop.22380 [source]

    Broadband coplanar waveguide-fed slot antenna for wireless local area networks and microwave imaging applications

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 4 2007
    Mohammod Ali
    Abstract A broadband CPW-fed semicircular slot antenna is proposed for 2,6 GHz WLAN (wireless local area networks) and microwave imaging applications. The total dimension of the bidirectional slot antenna is 80 mm by 50 mm and is designed on a 0.5-mm-thick Duroid 5880 substrate (dielectric constant = 2.2). The antenna operates from 2 to 6 GHz within VSWR of 2.5:1. The same antenna on a combination rectangular cylindrical cavity with cavity depth of 10 mm provides a directional beam, 11 dB front-to-back (F/B) ratio and a bandwidth of 63% (2.8,5.4 GHz). © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 846,852, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22276 [source]

    Compact meander monopole antenna for tri-band WLAN application

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 4 2007
    Li-Na Zhang
    Abstract A novel printed meander monopole antenna for tri-band wireless local area network (WLAN) applications is presented. The antenna is composed of a meander strip and a straight strip with a gap between the ends of them, both printed on an inexpensive FR4 substrate, and is fed by a 50 , microstrip feeder with the notched ground plane. The operation bandwidth of the proposed antenna covers 2.4, 5.2, and 5.8 GHz WLAN bands with light weight and compact radiator size of only 12 × 7 mm2. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 986,988, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22314 [source]

    An enhanced bandwidth planar inverted-F antenna with a modified shorting strip

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 3 2007
    Hoon Park
    Abstract This article presents a novel design method for a wideband planar inverted F-antenna that simultaneously covers GSM900, GPS, DCS1800, IMT2000, WLAN, and DMB services. The proposed antenna consisted of a main patch with stubs, an I-shaped patch, and a modified shorting strip. It had dimensions of 16 × 36 × 6 mm3. The dual band characteristic could be achieved by changing the length of a main patch. A very wide impedance bandwidth characteristic was obtained by optimizing the length of stubs, an I-shaped patch, and a modified shorting strip. Commercial electromagnetic software, CST Microwave Studio, was used to design the structure. The maximum gains at the frequencies of 915, 1576, 1785, 2170, 2400, and 2630 MHz were 1.0, 2.7, 5.4, 4.56, 1.52, and 2.95 dBi, respectively. The overall radiation pattern was suitable for mobile applications. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 513,515, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22179 [source]

    Modified stack inverted-F antenna with corner-truncated techniques for WLAN 2.4/5 GHz band applications

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2006
    Chung Ping Liu
    Abstract A modified design of stack inverted-F antenna with corner truncated technique for 2.4/5.0 GHz dual-band applications is presented in this paper. The new stack inverted-F antenna consists of two parts, one is M-shaped and the other is F-shaped. For current distributions, proposed F-shaped configuration determines the certain resonated frequencies of desired bands (4.98,5.25 GHz) and the M-shaped configuration depicts the range of 2.40,2.75 GHz. It is a compact and available microstrip antenna for IEEE 802.11a/b WLAN,s applications. Simulation and experimental results with frequency responses, radiation patterns, and current distributions are presented and discussed. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2378,2381, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21960 [source]

    Printed pentagon monopole antenna with a band-notched function

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2006
    Shun-Yun Lin
    Abstract In this study, we propose a design to obtain band-notching characteristics in printed planar monopoles. An ultra-wide band was achieved by means of the beveled upper edge of the rectangular patch with dimension as small as 55 mm2. On the other hand, it is necessary to notch certain bands to avoid interference from existing wireless local area network (WLAN), such as the 5.2 GHz band (5150,5350 MHz) and 5.8 GHz band (5725,5875 MHz), in spite of the adoption of the FCC for UWB communication systems operating between 3.1 and 10.6 GHz. This feature can be easily achieved by embedding an inverted-V-shape slot with length about one-half of the guided wavelength of the expected notched frequencies and along the boundary of the beveled radiating patch. This article presents the design of the proposed slotted monopole antenna, demonstrates the UWB operation with a notched frequency band, and analyzes the effects of the dimensions of the inverted-V-shape slot on the notched frequency band. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2016,2018, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21859 [source]