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Microwave Symposium (MMS), 2009 Mediterrannean

Date 15-17 Nov. 2009

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Displaying Results 1 - 25 of 84
  • Optimizing the communication paths in optimal Wireless Sensor Network deployment

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2900 KB) |  | HTML iconHTML  

    The deployment of wireless sensor network (WSN) forms a metric step to make the end of the desired system aim design. Deployment procedure can improve the information collected by giving more priority to the events which are more desired to be supervised; in addition, it can optimize the paths which link the network node among them as presented in this work. In this paper, we have improved the communication paths of an approach of optimal WSN deployment, in the aim to preserve the interest collected by the set of network nodes and improve the connectivity of the network. View full abstract»

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  • Services provisioning in ubiquitous mobile wireless environments

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (439 KB) |  | HTML iconHTML  

    Ubiquitous computing has gained momentum over the last years with the expansion of mobile devices. One area of pervasive computing is context-aware systems which are applications designed to react to the constant changes in the environment. This project presents a context aware platform that handles context acquiring and processing and manages the service provisioning. The platform alleviates the process of high level application development and sets a common ground for building applications and services. The context-based platform objective is to support mobile users with personalized services. It offers sophisticated mechanisms in matching the mobile user's preferences with services that are enabled at the visited location, and provides them in personalized and adaptive manner to the user. As a proof of concept, we present a case study on tourism where tourists are provided with services and information of interest based on their location and time. An application for e-tourism will be deployed on the top of the platform to assist tourists during their travels by providing them with context sensitive services. The user preferences, the current time, and the user current location are incorporated in the proactive formulation of suggestions on the tourist mobile devices about nearby points of interests (e.g. museums, restaurants...). View full abstract»

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  • A compact rectangular UWB Dielectric resonator antenna

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (8056 KB) |  | HTML iconHTML  

    A compact rectangular dielectric resonator antenna (DRA) is presented for ultra wide band communication systems. Ansoft HFSS 3-D electromagnetic solver is used for the design optimization. The proposed antenna has a low profile (~3), a small size and a low permittivity constant (10.2). An impedance bandwidth about 46% (from 6.9 to 11 GHz) was achieved making this antenna suitable for DS-UWB high band (i.e. 6 to 10.1 GHz) applications. View full abstract»

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  • Simulation and analysis of performance of LTE in indoor environments

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (885 KB) |  | HTML iconHTML  

    In this paper, system simulation for future 3GPP R8 Long Term Evolution (LTE) radio access channel in indoor environment is presented. 3D ray tracing algorithms have been developed in order to analyze coverage-capacity considerations regarding high order modulation schemes present in LTE. The results aid in modeling the behavior of high speed data services in future 4G systems in indoor environments. View full abstract»

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  • Quality of service in MAQAME Architecture

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (224 KB) |  | HTML iconHTML  

    Due to the advance in Wireless technology, ubiquitous Internet access, and improvements to mobile device technology, mobile services flourishe considerably and will continue to do so as the number of mobile users begins to multiply. However, this range of published mobile services introduces a new challenging problem, in addition to the diversity of discovery protocols and the heterogeneity of interaction protocols. This challenge concerns the ability to find at runtime relevant mobile services in term of QoS for users among those implementing similar functionalities according to their device constraints and their preferences. To this end and taking into account the diversity of QoS specification languages, we present in this paper an approach to determine at runtime the appropriate needed mobile service related to device capabilities, client preferences, execution context and mobile service features. This approach is currently under implementation on MAQAME Architecture suggested in a previous work. View full abstract»

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  • Fast convergence mechanisms and features deployment within operator backbone infrastructures

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (191 KB) |  | HTML iconHTML  

    The goal of backbone operators like: Orange/France telecom, Cegetel, AT&T, Sprint, BT...etc, is minimizing impact on customer applications due to failures and interruptions within their backbone. Data backbones based on MPLS/VPN infrastructures are widely deployed over the world, giving connectivity to enterprises and public users with on demand added services. Ideally: customers will see no interruption at all, tending to make backbone failures as transparent as possible to end applications. That is why tuning configuration of routers and routing mechanisms, introducing features that help to minimize interruption durations within the backbone. In this paper we will give an overview of fast convergence mechanisms and features deployment within data network infrastructures. Will be discussed standard features like: ¿bidirectional failure detection¿ (BFD) which provides fast failure detection for all media types, encapsulations, topologies, and routing protocols, and how it is the way to go when the physical media does not provide any way of detecting a failure, fast enough to meet fast convergence design requirement, MPLS ldp-igp synchronization: which ensures that LDP is fully established before the IGP path is used for switching. It achieves this by not building IGP neighbor-ship before the LDP neighbor-ship is established, will be discussed also some other relevant features. View full abstract»

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  • ANFIS method for forecasting internet traffic time series

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3906 KB) |  | HTML iconHTML  

    In this paper we have applied the adaptive neuro-fuzzy inference system (ANFIS) which is realized by an appropriate combination of fuzzy systems and neural networks for forecasting a set of input and output data of Internet traffic time series. Several statistical criteria are applied to provide the effectiveness of this model. The obtained results demonstrate that the ANFIS model present a good precision in the prediction process of internet traffic in terms of statistical indicators. This model fits well real data and provides an effective description of network condition at different times. View full abstract»

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  • A novel compact multiband planar antenna for wireless and mobile handsets

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (330 KB) |  | HTML iconHTML  

    In this paper, a novel printed compact multiband planar antenna is proposed for wireless and mobile handsets. The radiating patch of this antenna is designed jointly with the shape of the ground plane. This antenna covers the 3G universal mobile telecommunication system (UMTS; 1920-2170 MHz), Bluetooth (2400-2484 MHz), Wi-Fi (2400-2484, 4900-5000, 5150-5250, 5150-5350, 5470-5725 MHz] and Worldwide Interoperability for Microwave Access [Wimax; [(2400-2600), (3400-3600)] MHz]. The features of each band can be easily optimized by tuning the position, shape, and size of the embedded slots in the radiating patch, and the height of substrate. This antenna performances were optimized using CST simulator and were validated using Ansoft HFSS. View full abstract»

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  • Comparing accuracy for ML, MUSIC, ROOT-MUSIC and spatially smoothed algorithms for 2 users

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2678 KB) |  | HTML iconHTML  

    In this article we simulate four famous algorithms in DOA and then compare the algorithms based on their finding and estimating of the accuracy level angels from two different users, having demonstrated the result of simulation of the four algorithms in comparison tables, it is observed that ROOT-MUSIC algorithm have high level of accuracy in estimation of close angles(28, 30 degrees). MUSIC, Spatially Smoothed and ML algorithms have the next steps in accuracy respectively. View full abstract»

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  • Two-dimensional Forward-Backward Time-Stepping approach for tumor detection in dispersive breast tissues

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (5233 KB) |  | HTML iconHTML  

    The Forward-Backward Time-Stepping (FBTS) technique is applied to determine the presence and location of malignant tumor in the heterogeneous breast model. A new strategy is integrated in the FBTS algorithm to accurately estimate the dielectric properties of tissues. We demonstrate 2-D FBTS technique utilizing the numerical dispersive breast model in a free space. This new strategy manipulating Debye dispersion equation is proposed to treat dispersive case. Numerical simulation results show the FBTS algorithm has the potential to provide useful quantitative information of the breast's internal composition. View full abstract»

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  • Improving Ambiguity Function of Costas signal

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (6247 KB) |  | HTML iconHTML  

    This paper presents the effects of modifying Costas signal in time and frequency to improve ambiguity function (AF). The effect of adding frequency spacing, linear frequency modulation, constant space time, and variable space time between sub-pulses of Costas signal are presented and compared. It is shown that a considerable reduction of side-lobe and better Doppler resolution is achieved by using variable spacing between sub-pulses of Costas signal. View full abstract»

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  • Compact internal antenna for multi standard operations in the mobile phone

    Page(s): 1 - 7
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (5674 KB) |  | HTML iconHTML  

    In this paper, the authors will discuss different design of a multiband compact antenna for the integration into the new multi function mobile phones. The antenna is matched to operate at GSM 920 MHz, WI-Fi 2.4 Ghz and HiperLan 5.1 GHz standards with low SAR levels. Return loss coefficient and radiation pattern of this antenna are computed in free space as well as in the presence of head. The specific absorption rate (SAR) of the planar antenna is calculated and compared with that of the monopole antenna. To examine the performance of this antenna, a prototype was designed, fabricated and measured; the simulation analysis was performed using the HFSS software, good agreement with the simulation providing validation of the design procedure. View full abstract»

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  • Investigation of residual stress effects and modeling of spring constant for RF MEMS switches

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2327 KB) |  | HTML iconHTML  

    Any film which is deposited during the fabrication undergoes some form of stress. It can be either a compressive stress or tensile stress. It is important to have right value of either compressive or tensile stress for the particular application. In this paper we present an investigation of the stresses generated by the gold thin film during the fabrication process of RF MEMS switches. During the fabrication of RF MEMS series switches a small value of tensile stress is intentionally generated so that beam does not lead to stiction after final release. We are also briefly presenting a new mathematical model for calculation of the spring constant of the beam structures. The method we used is based on the Euler-Bernoulli beam equations. The spring constants calculated for two new beam designs were 3.37 N/m and 3.31 N/m respectively. View full abstract»

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  • Design and optimization of a two-way Gysel power divider with arbitrary power division and impedance matching

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (6279 KB) |  | HTML iconHTML  

    Since the common microstrip power dividers are generally low power devices, in this paper a modified wideband Gysel power divider is proposed, which possesses high power handling capabilities and arbitrary power division. The proposed divider configuration has the provision of heat transfer by resistors connected to the ground plane through vias. The divider structure is devised in such a way that voltage distributions in its two half circuit are symmetrical and the even-and odd- mode analysis may be applied. The method of least squares (MLS) is used to develop an algorithm for its design and optimization, which also incorporates impedance matching among its input and output ports. The widths and lengths of line sections are determined in the design procedure. the proposed power divider and its MLS design algorithm are verified by the electromagnetic softwares. View full abstract»

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  • Slow light for microwave photonics applications

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (5079 KB) |  | HTML iconHTML  

    This paper focuses in slow light and its application in microwave photonics. It makes a brief review of microwave photonics evolution from its inception to new emerging topics. Subsequently, the principles, techniques, and applications of slow light in microwave photonics are addressed more in depth. Finally, the photonic crystal approach is presented as a promising approach to slow-light-based microwave photonics devices. The peculiar design flexibility of this approach is demonstrated with a series of simulations. View full abstract»

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  • Novel microwave planar bandpass filter structures with strongly asymmetric characteristics

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (5341 KB) |  | HTML iconHTML  

    In this paper the problem of designing simple low-cost planar microwave bandpass filters with strongly asymmetric characteristics, filters that can very efficiently attenuate one of the two adjacent channels, is investigated. In case of a fourth-order filter, the usual quadruplet structure leads to two transmission zeros located one on each side of the passband, but higher attenuation can be obtained for one of the two adjacent channels by designing filters with two transmission zeros in the same (upper or lower) stopband. The new topology investigated in this paper offers the possibility of designing such quadruplets with two transmission zeroes situated both on the same side of the passband, in prescribed and controlled positions. Filters with this novel structure can provide very high attenuation not only at a single frequency, but in a larger adjacent frequency band. View full abstract»

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  • Improvement in the stopband of a microwave lowpass filter utilizing resonance structures

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (5299 KB) |  | HTML iconHTML  

    Different strategies have been suggested to improve the stop band of microwave lowpass filters and to suppress the spurious responses in the stop band. Resonance structures can be utilized in various microwave applications to improve the performance. In this article, a special form of a resonance structure is introduced which assists in achieving a deep stop band for microwave LP filters. Simulations are presented to support the usefulness of the structure suggested. View full abstract»

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  • A novel model for complex permittivity of glass for propagation modeling in millimeter-wave band

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1653 KB) |  | HTML iconHTML  

    In radio channels modelings, the phases and amplitudes of the rays undergo some modifications when they are reflected from or transmitted through a particular material. These reflection and transmission coefficients make use of the electrical properties of the materials, thus, it is essential to know the values of the relative dielectric constant and of the conductivity or the loss tangent of the materials that appear in the propagation environments. In this paper, a theoretical model based on the inter-molecule interactions, has been developed and used to estimate the dielectric parameters of glass. View full abstract»

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  • An 18Ghz LNA Ga FET high gain amplifier for WLAN

    Page(s): 1 - 3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (6358 KB) |  | HTML iconHTML  

    In this article we design a novel ka band low noise amplifier with high stability. in this design Ga FET used to high gain and low noise figure and conditional and unconditional stability. We applied a low noise cost solution for various Ka band receivers such as P-to-P radio, WLAN and UWB sensors. Finally circuit layout with ADS software is presented and very low noise figure about 1.3 dB and about 16 dB gain was taken. View full abstract»

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  • Optical Single Side band modulator based on dual arm MZM and aplications

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2683 KB) |  | HTML iconHTML  

    Optical single side band is a format that proves to be very efficient when dispersion is present in the fiber. This paper reports the construction and optimization of a broadband optical single sideband prototype. We present our work in the implementation of optical single-sideband (OSSB) modulation and in the application of this modulation format for baseband transmission and microwave photonics. We report on the optimization of an optical single sideband (OSSB) prototype transmitter 10 Gbit/s data rates. The system robustness to chromatic dispersion as well as the efficiency of the electric chromatic dispersion compensation were evaluated and reported. View full abstract»

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  • Surface plasmon polariton propagation in metallic channels analized by spatio-temporal FEM model (ST-FEM)

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (5828 KB) |  | HTML iconHTML  

    The analysis of surface plasmon polariton (SSP) propagation through a long nano-metallic channel by a spatio-temporal finite element model is presented in detail for the first time. Interesting results showing the evolution of the signal's temporal information together with the signal's transverse spatial distribution along the channel's axis will be reported. View full abstract»

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  • Simulation and analysis of performance of indoor meshed ZigBee networks

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (7632 KB) |  | HTML iconHTML  

    In this paper, system simulation for indoor meshed ZigBee networks is presented. The behavior of the radio channel is evaluated by means of 3D ray tracing algorithms that have been developed in order to analyze interference in a scenario of coexistence of two ZigBee meshed networks which are adjacent one to the other by electromagnetic transparent wall conditions. As a result, coverage plots, EVM values and SNR relations are obtained in the simulation space. The result aid in modeling the behavior ZigBee systems in indoor environments, as well as in adequate planning of large sensor networks based on ZigBee. View full abstract»

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  • Design of a novel circularly polarized microstrip patch antenna using EBG structure

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (5412 KB) |  | HTML iconHTML  

    In this paper a novel circularly polarized dual-feed microstrip patch antenna is proposed and also electromagnetic band-gap (EBG) structures are utilized to enhance the antenna efficiency and bandwidth. The microstrip patch is a square with a chamfered corner and a cross-slot of equal arm lengths. It is fed by 50 ¿ two microstrip lines. The proposed antenna is designed to work on a substrate Taconic RF-30 that has a thickness of 0.76 mm and relative permittivity (¿r) of 2.92. This substrate has several vacuum holes for realization EBG. The proposed structure is designed and simulated by Ansoft HFSS software. Effects of varying the parameters of the patch antenna on the performance of the antenna have also been studied. View full abstract»

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  • Analysis and synthesis of a K-band microstrip patch antenna array

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3394 KB) |  | HTML iconHTML  

    This paper describes the synthesis of a microstrip linear antenna array operating at 24 GHz frequency. A linear array with 5 elements, called the 1×5 array, has been considered and Dolph-Chebyshev method has been used for synthesizing. It has investigated how the performance properties of a linear array are affected by varying some parameters such as N-element, inter-element spacing (d) on radiation pattern. It has been observed that the simulated results of an array factor compare positively with the different types of design used in the state of the art results. View full abstract»

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  • The scattering the TEM mode at the junction of perfectly conducting and dielectric loaded grooved coaxial waveguides

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2191 KB) |  | HTML iconHTML  

    A rigorous Wiener-Hopf solution is derived for the analysis of coaxial waveguides with dielectric filled semi-infinite grooves in the inner and outer conductors. Such discontinuities can serve useful impedance matching functions in microwave circuits and may exhibit band stop filter characteristics. View full abstract»

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