Résumé: Le travail présenté dans cet article se rapporte à l'optimisation de la synthèse des diagrammes de rayonnements de réseau d'antennes linéaires. La méthode de synthèse mise en oeuvre pour ce type de réseaux permet... more
Résumé: Le travail présenté dans cet article se rapporte à l'optimisation de la synthèse des diagrammes de rayonnements de réseau d'antennes linéaires. La méthode de synthèse mise en oeuvre pour ce type de réseaux permet d'approcher à un diagramme de rayonnement désiré et trouver les pondérations complexes w ij pour que la fonction F R (ө,φ) réponde à des spécifications précises, souvent d'écrites par un gabarit. L'approche utilisée est basée sur de la méthode de Dolph-Tchebycheff et sur les réseaux de neurones qui sont capables de modéliser les diagrammes de rayonnements de réseau d'antennes linéaires, compte tenu de critères généraux prédéterminés, et finalement il permet de prédire le diagramme désiré à partir du modèle neural. Notre contribution principale dans cet article est l'extension d'un modèle de synthèse des diagrammes de rayonnement de ces réseaux à partir des pondérations. Mots clés : Réseau d'antennes linéaires, modélisation, réseau...
Résumé: L'objectif de cet article est l'étude du phénomène de rayonnement du réseau d'antennes linéaire lorsque les sources sont pondérées, en particulier comment choisir la loi de pondérations pour que la répartition spatiale... more
Résumé: L'objectif de cet article est l'étude du phénomène de rayonnement du réseau d'antennes linéaire lorsque les sources sont pondérées, en particulier comment choisir la loi de pondérations pour que la répartition spatiale de la puissance rayonnée par le réseau considère satisfasse à des contraintes que l'on se fixe. La synthèse développée est basée sur la méthode de Dolphh-Tchebycheff. Mots clés : Réseaux d'antennes Dolph-Tchebycheff, synthèse, optimisation, diagramme de rayonnement.
ABSTRACT This paper describes a wideband resonant patch antenna for GSM system applications. A thick substrate is used to increase the bandwidth of such antenna. A new design method is suggested to solve the problem due to the inductance... more
ABSTRACT This paper describes a wideband resonant patch antenna for GSM system applications. A thick substrate is used to increase the bandwidth of such antenna. A new design method is suggested to solve the problem due to the inductance created by the probe feed. The 3D FDTD is used for the simulation of the antenna. A wide impedance matching bandwidth of 8% was reached. A good agreement is obtained between theoretical and practical results.
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In this paper, we propose two approaches to provide direction of arrival using homodyne detection systems technologies like six-port and five port reflectometers. The choice of the reflectometers' type becomes critical in parallel of... more
In this paper, we propose two approaches to provide direction of arrival using homodyne detection systems technologies like six-port and five port reflectometers. The choice of the reflectometers' type becomes critical in parallel of the circuit capability, i.e. in terms of the number of signals to be detected simultaneously. We present our study by implementing MUSIC algorithm at the output of two different homodyne receivers. The results are deduced from the simulation of the characteristics of each system, using the Advanced Design System (ADS) and MATLAB.
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In this paper, we present a theoretical study on the interests of a 1D (one-dimensional) EBG Matrix versus the patch array, in terms of mutual coupling and grating lobes. To prove this interest, a comparison is made between these two... more
In this paper, we present a theoretical study on the interests of a 1D (one-dimensional) EBG Matrix versus the patch array, in terms of mutual coupling and grating lobes. To prove this interest, a comparison is made between these two antenna systems. The aim of this paper is to offer new antenna systems to the market for specific applications.
This paper presents an experimental validation of a novel antenna system called “electromagnetic band gap matrix antenna”. The theoretical concept is based on the equivalent radiating surface approach and the antenna design is inspired... more
This paper presents an experimental validation of a novel antenna system called “electromagnetic band gap matrix antenna”. The theoretical concept is based on the equivalent radiating surface approach and the antenna design is inspired from the electromagnetic band gap antennas. In this paper, an experimental validation is demonstrated to validate the theoretical concept of the antenna and several electromagnetic performances such as the low mutual coupling and the beam steering.
This paper presents an experimental validation of a developed feeding technique applied to a novel antenna system called electromagnetic band gap matrix antenna. The experimental validation will not only demonstrate the theoretical... more
This paper presents an experimental validation of a developed feeding technique applied to a novel antenna system called electromagnetic band gap matrix antenna. The experimental validation will not only demonstrate the theoretical concept of the antenna, but it will also show the efficiency of applying a developed excitation law which enables us to obtain a sectorial radiation pattern presenting a quasi-constant gain over an angular range of 18° with low side lobes level less than -20 dB. The feeding technique process is described in this paper and some experimental results are presented to demonstrate the beam forming and steering capabilities of the matrix antenna.
ABSTRACT An experimental validation for the concept of a novel agile electromagnetic band gap matrix antenna is presented. It is used for beam forming and steering. It is fed by a cardinal sine excitation. A sectorial pattern is obtained.... more
ABSTRACT An experimental validation for the concept of a novel agile electromagnetic band gap matrix antenna is presented. It is used for beam forming and steering. It is fed by a cardinal sine excitation. A sectorial pattern is obtained. This pattern presents a special shape with low side lobes level. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:533–537, 2015
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ABSTRACT An adaptive antenna system consists of a combination of multiple antenna elements with a signal-processing capability to optimize its radiation and/or reception pattern automatically in response to the signal environment. In a... more
ABSTRACT An adaptive antenna system consists of a combination of multiple antenna elements with a signal-processing capability to optimize its radiation and/or reception pattern automatically in response to the signal environment. In a telecommunication system, adaptive antenna system is the port through which radio frequency (RF) energy is coupled from the transmitter to the environment and, in reverse, to the receiver from the environment. In this paper, an efficient method for the pattern synthesis of the linear antenna arrays with the prescribed nulling and steering lobe is presented. The proposed method is based on LMS algorithm. This paper proposes the novel architecture for implementing a least mean square (LMS) algorithm, using an 8 quasi-Yagi array with its feeding system.
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This paper presents the axial ratio beamwidth results obtained by different sequentially rotated microstrip patch antenna sub-array configurations. Simplified formulae of electrical radiation pattern allow a direct polarization... more
This paper presents the axial ratio beamwidth results obtained by different sequentially rotated microstrip patch antenna sub-array configurations. Simplified formulae of electrical radiation pattern allow a direct polarization estimation. To validate these formulae, a comparison with a rigorous calculation code using the Finite Difference Time Domain method (F.D.T.D.), through same cases simulated, gives good agreement. Finally, excitation errors introduced in simple analytical expressions are taken into account for two particular sub-arrays.
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... Olleik Charif", Rammal Mohammad", Fadlallah Najib 2 , ... 12. .!lO'O +-~-"T"-..._r-....T-""""I'-... IDA We found that, the module of S11 is less... more
... Olleik Charif", Rammal Mohammad", Fadlallah Najib 2 , ... 12. .!lO'O +-~-"T"-..._r-....T-""""I'-... IDA We found that, the module of S11 is less than or equal -10dB (SWR ::::; 2) or a band of frequency of 200 MHz approximately around the central frequency. IV. ...