Mohammad Rammal - Academia.edu (original) (raw)
Papers by Mohammad Rammal
Résumé: Le travail présenté dans cet article se rapporte à l'optimisation de la synthèse des ... 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'... 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.
Proceedings of the Twentieth National Radio Science Conference (NRSC'2003) (IEEE Cat. No.03EX665), 2003
ABSTRACT This paper describes a wideband resonant patch antenna for GSM system applications. A th... 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.
In this paper, we propose two approaches to provide direction of arrival using homodyne detection... 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.
In this paper, we present a theoretical study on the interests of a 1D (one-dimensional) EBG Matr... 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 ... 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 nove... 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.
The phased antenna array consists of a combination of multiple antenna elements with a signal-pro... more The phased antenna array 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, the phased antenna array 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, a novel design of phased antenna array based on digital beamforming is proposed. The goal of the design is to construct smart antenna beamforming systems with hardware-software implemented neural network. A newly proposed synthesis method is used to design antenna arrays capable of delivering a much better radiation performance in terms of homogenous coverage and reduced interference with phased arrays and capable to beamforming and electronic steering by adjusting the relative phases of the signal received or transmitted by each antenna. To verify the performances of the proposed technique, an 8-element array has been realized and tested for various types of beam configurations.
2014 International Radar Conference, 2014
This paper presents an agile radiating matrix antenna which is formed by an association of severa... more This paper presents an agile radiating matrix antenna which is formed by an association of several and identical special radiating elements called 'pixels'. Those pixels have special properties concerning its radiating apertures. The matrix antenna working principle is based on the equivalent radiating surface approach and not on the classical array approach. The aim of this paper is to show the matrix antenna performances concerning its ability to achieve a great beam steering for high scanning angles which is used for target following and military bases monitoring in radar applications. The principle of this antenna constitutes the subject of an accepted CNRS (Centre National de la Recherche Scientifique) patent.
Microwave and Optical Technology Letters, 2015
ABSTRACT An experimental validation for the concept of a novel agile electromagnetic band gap mat... 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
2009 16th IEEE International Conference on Electronics, Circuits and Systems - (ICECS 2009), 2009
ABSTRACT An adaptive antenna system consists of a combination of multiple antenna elements with 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.
2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2014
In newborns, a poor coordination between sucking, swallowing and breathing may undermine the effe... more In newborns, a poor coordination between sucking, swallowing and breathing may undermine the effectiveness of oral feeding and signal immaturity of Central Nervous System. The aim of this work is to develop and validate a non-invasive device for recording respiratory events of newborns during bottle feeding. The proposed device working principle is based on the convective heat exchanged between two hot bodies and the infants' breathing. The sensing elements are inserted into a duct and the gas exchanged by infants is conveyed into this duct thanks to an ad hoc designed system to be mounted on a commercial feeding bottle.
2007 IEEE Radar Conference, 2007
Patch antennas plane networks have been used largely in communication systems. Their capability t... more Patch antennas plane networks have been used largely in communication systems. Their capability to change radiation pattern electronically, multi-beam capacity and high spatial resolution has made them attractive for mobile communication applications. The work presented in this paper refers to the synthesis of periodic patch antennas plane networks supplied with coaxial lines. The method of synthesis used for this type of networks let's possible an optimal approach for the desired radiation pattern specified by a gauge sensible for source excitation and space distribution of the radiant sources. The development of the synthesis is based on the neural networks technique.
2009 16th IEEE International Conference on Electronics, Circuits and Systems - (ICECS 2009), 2009
This paper describes a new approach to cylindrical antenna controlled by the excitation (amplitud... more This paper describes a new approach to cylindrical antenna controlled by the excitation (amplitude and phase) to synthesize directive lobe and multilobe patterns, and create adaptive nulls in interference direction and large lobe pattern. The proposed method is based on iterative minimization of a function that incorporates constraints imposed in each direction with respect to excitation (amplitude and phase). To verify the performances of the proposed technique, an 16-element cylindrical antenna has been simulated for various types of beam configurations.
Progress In Electromagnetics Research, 2006
The performance of mobile cellular radio networks is limited by the level of cochannel interferen... more The performance of mobile cellular radio networks is limited by the level of cochannel interference that can be tolerated. The use of antennas arrays is very helpful in enhancing the performance and capacity of the wireless communication system. This paper presents a method for antenna pattern synthesis that suppress multiple interfering narrow or wide band signals while receiving the desired signal by controlling only the phase. Excitation phases are computed using the Sequential Quadratic Programming (SQP) technique. This method transforms the nonlinear minimization (or maximization) problem to a sequence of quadratic subproblems, based on a quadratic approximation of the Lagrangian function. 252 Mouhamadou et al.
Microwave and Optical Technology Letters, 1996
ABSTRACT
Microwave and Optical Technology Letters, 1994
A method of designing a series-fed microstrip traveling-wave array to produce a shaped pattern is... more A method of designing a series-fed microstrip traveling-wave array to produce a shaped pattern is described. A theoretical analysis of the traveling-wave element is given and experimental results are presented. High efJiciency and good directivity have been observed on the array. ABSTRACT A method of designing a series-fed microstrip traveling-wave array to produce a shaped pattern is described. A theoretical analysis of the traveling-wave element is given and experimental results are presented. High efJiciency and good directivity have been observed on the array. 0 ABSTRACT Plane-wave propagation in an anisotropic chiral medium with isotropic permittivity and permeability and symmetric chirality dyadic is considered. The eigenvalue equation is formed and the wave numbers and the corresponding eigenpolarizations are given. The results make possible the construction of a polarization transformer in which one can also choose the handedness. 0 I994 John Wiley & Sons, Inc.
Résumé: Le travail présenté dans cet article se rapporte à l'optimisation de la synthèse des ... 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'... 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.
Proceedings of the Twentieth National Radio Science Conference (NRSC'2003) (IEEE Cat. No.03EX665), 2003
ABSTRACT This paper describes a wideband resonant patch antenna for GSM system applications. A th... 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.
In this paper, we propose two approaches to provide direction of arrival using homodyne detection... 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.
In this paper, we present a theoretical study on the interests of a 1D (one-dimensional) EBG Matr... 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 ... 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 nove... 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.
The phased antenna array consists of a combination of multiple antenna elements with a signal-pro... more The phased antenna array 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, the phased antenna array 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, a novel design of phased antenna array based on digital beamforming is proposed. The goal of the design is to construct smart antenna beamforming systems with hardware-software implemented neural network. A newly proposed synthesis method is used to design antenna arrays capable of delivering a much better radiation performance in terms of homogenous coverage and reduced interference with phased arrays and capable to beamforming and electronic steering by adjusting the relative phases of the signal received or transmitted by each antenna. To verify the performances of the proposed technique, an 8-element array has been realized and tested for various types of beam configurations.
2014 International Radar Conference, 2014
This paper presents an agile radiating matrix antenna which is formed by an association of severa... more This paper presents an agile radiating matrix antenna which is formed by an association of several and identical special radiating elements called 'pixels'. Those pixels have special properties concerning its radiating apertures. The matrix antenna working principle is based on the equivalent radiating surface approach and not on the classical array approach. The aim of this paper is to show the matrix antenna performances concerning its ability to achieve a great beam steering for high scanning angles which is used for target following and military bases monitoring in radar applications. The principle of this antenna constitutes the subject of an accepted CNRS (Centre National de la Recherche Scientifique) patent.
Microwave and Optical Technology Letters, 2015
ABSTRACT An experimental validation for the concept of a novel agile electromagnetic band gap mat... 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
2009 16th IEEE International Conference on Electronics, Circuits and Systems - (ICECS 2009), 2009
ABSTRACT An adaptive antenna system consists of a combination of multiple antenna elements with 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.
2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2014
In newborns, a poor coordination between sucking, swallowing and breathing may undermine the effe... more In newborns, a poor coordination between sucking, swallowing and breathing may undermine the effectiveness of oral feeding and signal immaturity of Central Nervous System. The aim of this work is to develop and validate a non-invasive device for recording respiratory events of newborns during bottle feeding. The proposed device working principle is based on the convective heat exchanged between two hot bodies and the infants' breathing. The sensing elements are inserted into a duct and the gas exchanged by infants is conveyed into this duct thanks to an ad hoc designed system to be mounted on a commercial feeding bottle.
2007 IEEE Radar Conference, 2007
Patch antennas plane networks have been used largely in communication systems. Their capability t... more Patch antennas plane networks have been used largely in communication systems. Their capability to change radiation pattern electronically, multi-beam capacity and high spatial resolution has made them attractive for mobile communication applications. The work presented in this paper refers to the synthesis of periodic patch antennas plane networks supplied with coaxial lines. The method of synthesis used for this type of networks let's possible an optimal approach for the desired radiation pattern specified by a gauge sensible for source excitation and space distribution of the radiant sources. The development of the synthesis is based on the neural networks technique.
2009 16th IEEE International Conference on Electronics, Circuits and Systems - (ICECS 2009), 2009
This paper describes a new approach to cylindrical antenna controlled by the excitation (amplitud... more This paper describes a new approach to cylindrical antenna controlled by the excitation (amplitude and phase) to synthesize directive lobe and multilobe patterns, and create adaptive nulls in interference direction and large lobe pattern. The proposed method is based on iterative minimization of a function that incorporates constraints imposed in each direction with respect to excitation (amplitude and phase). To verify the performances of the proposed technique, an 16-element cylindrical antenna has been simulated for various types of beam configurations.
Progress In Electromagnetics Research, 2006
The performance of mobile cellular radio networks is limited by the level of cochannel interferen... more The performance of mobile cellular radio networks is limited by the level of cochannel interference that can be tolerated. The use of antennas arrays is very helpful in enhancing the performance and capacity of the wireless communication system. This paper presents a method for antenna pattern synthesis that suppress multiple interfering narrow or wide band signals while receiving the desired signal by controlling only the phase. Excitation phases are computed using the Sequential Quadratic Programming (SQP) technique. This method transforms the nonlinear minimization (or maximization) problem to a sequence of quadratic subproblems, based on a quadratic approximation of the Lagrangian function. 252 Mouhamadou et al.
Microwave and Optical Technology Letters, 1996
ABSTRACT
Microwave and Optical Technology Letters, 1994
A method of designing a series-fed microstrip traveling-wave array to produce a shaped pattern is... more A method of designing a series-fed microstrip traveling-wave array to produce a shaped pattern is described. A theoretical analysis of the traveling-wave element is given and experimental results are presented. High efJiciency and good directivity have been observed on the array. ABSTRACT A method of designing a series-fed microstrip traveling-wave array to produce a shaped pattern is described. A theoretical analysis of the traveling-wave element is given and experimental results are presented. High efJiciency and good directivity have been observed on the array. 0 ABSTRACT Plane-wave propagation in an anisotropic chiral medium with isotropic permittivity and permeability and symmetric chirality dyadic is considered. The eigenvalue equation is formed and the wave numbers and the corresponding eigenpolarizations are given. The results make possible the construction of a polarization transformer in which one can also choose the handedness. 0 I994 John Wiley & Sons, Inc.