Chadi Nader - Academia.edu (original) (raw)

Papers by Chadi Nader

J Phys Iv, 2005

Some microwave passive components (such as circulators, isolators, ... etc) still use bulk magne... more Some microwave passive components (such as circulators, isolators, ... etc) still use bulk magnetic materials. A method for the dielectric and magnetic characterization of multi-layer materials in the microwave range is presented as well as its reliability and its domain of validity. It allows to determine the elements of the permeability tensor of gyromagnetic slab. This method of material characterization can be implemented at various microwave bands by changing the geometrical dimensions of the rectangular waveguide.

HAL (Le Centre pour la Communication Scientifique Directe), May 7, 2008

International audienc

Le developpement des systemes de telecommunications et de detection dans le domaine des hyperfreq... more Le developpement des systemes de telecommunications et de detection dans le domaine des hyperfrequences necessite la miniaturisation et l'integration de composants passifs micro-ondes. Le Laboratoire Dispositifs et Instrumentations en Optoelectronique et Micro-ondes (DIOM) s'est oriente vers la fabrication de couches minces magnetiques sur des substrats dielectriques d'epaisseur inferieure a 1 mm, dont l'objectif est la realisation de composants passifs miniatures qui doivent fonctionner au dela de 1 GHz. La connaissance des proprietes electromagnetiques du materiau utilise permet de fournir les elements essentiels a la modelisation de ce materiau en vue d'une simulation complete du composant. L'objectif de cette these est la caracterisation hyperfrequence de materiaux dielectriques et magnetiques anisotropes a l'etat solide et d'une epaisseur inferieure a 1 mm ainsi que de couches avec leurs substrats. Une methode de caracterisation en guide rectangulaire dans le bande X (8. 2 - 12. 4 GHz) puis en bande Ka (26. 5 - 40 GHz) a ete mise en œuvre et a permis de determiner les proprietes dielectriques et magnetiques d'echantillons en structure multicouche. L'application de cette methode aux couches minces magnetiques elaborees au laboratoire DIOM nous a permis de mettre en evidence des effets non reciproques pour des couches de YIG (ferrite Grenat) d'epaisseur de l'ordre de 4aem. Enfin, la transposition de cette methode vers la bande Ka a ete validee dans le cas de materiaux dielectriques

International Journal of Applied Electromagnetics and Mechanics, 2008

The paper investigates the numerical calculation of the electrical coils belonging to the inducti... more The paper investigates the numerical calculation of the electrical coils belonging to the inductive transducers with magnetic fluids for inclinations and aerodynamic measurements. One way to improve the construction of these transducers is to increase the electrical frequency for their coils. In this case, the thickness of the coils can be reduced by a large amount. The paper presents a numerical model for calculating the inductance of these ultra thin coils versus the level of the magnetic fluid core, the geometrical dimensions, and the magnetic properties of materials.

Progress In Electromagnetics Research C, 2011

Progress In Electromagnetics Research M, 2011

We propose a metamaterial coplanar stop-band filter made of multi-turn rectangular spiral particl... more We propose a metamaterial coplanar stop-band filter made of multi-turn rectangular spiral particles. Numerical and experimental results show the feasibility of devices with dimensions more than 10 times smaller than those in the literature and with good performances.

EPJ Web of Conferences, 2014

In telecommunication systems, heavy bulky magnets are used to establish the proper functioning of... more In telecommunication systems, heavy bulky magnets are used to establish the proper functioning of a circulator by ensuring the uniform orientation of the ferrite material's magnetic moment. Thus to develop an unbiased coplanar microwave circulator, the approach based on "ferromagnetic nanowired composite substrates" was promising. The idea was to do a magnetophoretic deposition of nanocoloidal cobalt ferrite nanoparticles into porous alumina membranes and permanently orient them uniformly. Therefore, in order to check the orientation possibility of the nanoparticle, samples of magnetic thin films on glass substrates were synthetized from CoFe 2 O 4 nanoparticles dispersed in a silica sol-gel matrix using the dip-coating technique with and without a uniformly applied magnetic field. To investigate the magnetic behavior of the prepared samples, the Faraday rotation as a function of the applied magnetic field was measured using a spectral polarimeter. The unambiguous qualitative difference between the Faraday rotation hysteresis loops shows a large variation of coercive (μ 0 H c) and remanent field () values, thus proving the orientation of the nanoparticles. Such nanocomposite is a promising candidate for future miniature microwave circulators fabrication.

Advanced Materials Research, 2011

A microstrip bandpass filter with rectangular patch coupled resonator is presented. The filter is... more A microstrip bandpass filter with rectangular patch coupled resonator is presented. The filter is designed to be more affected by the dielectric layer above the conductors compared to the same type of parallel-coupled bandpass filter. The filter is designed to operate between 1 GHz to 3 GHz and this can be a sensor base on distributed capacitors. The agreement between the circuit simulator and measured results is excellent and gives a very good prediction for the filter characteristics. The aim of this prototype filter is to show insertion loss (IL) at the bandpass transmission response when a dielectric material is above or near the conductors. A large study around the sensibility and the effect of the dielectric layer is done in order to evaluate its performance in detection and dielectric characterization.

Advanced Materials Research, 2011

in this paper, we propose a new multi-band patch antenna structure for embedded RFID (Radio Frequ... more in this paper, we propose a new multi-band patch antenna structure for embedded RFID (Radio Frequency Identification) readers and wireless communications. The proposed antenna is a dual band microstrip patch antenna using U-slot geometry. The operating frequencies of the proposed antenna are chosen as 2.4 and 0.9 (GHz), obtained by optimizing the physical dimensions of the U-slot. Several parameters have been investigated using Ansoft Designer software. The antenna is fed through a quarter wavelength transformer for impedance matching. An additional layer of alumina is added above the surface of the conductors to increase the performance of the antenna.

Http Www Theses Fr, 2004

Le developpement des systemes de telecommunications et de detection dans le domaine des hyperfreq... more Le developpement des systemes de telecommunications et de detection dans le domaine des hyperfrequences necessite la miniaturisation et l'integration de composants passifs micro-ondes. Le Laboratoire Dispositifs et Instrumentations en Optoelectronique et Micro-ondes (DIOM) s'est oriente vers la fabrication de couches minces magnetiques sur des substrats dielectriques d'epaisseur inferieure a 1 mm, dont l'objectif est la realisation de composants passifs miniatures qui doivent fonctionner au dela de 1 GHz. La connaissance des proprietes electromagnetiques du materiau utilise permet de fournir les elements essentiels a la modelisation de ce materiau en vue d'une simulation complete du composant. L'objectif de cette these est la caracterisation hyperfrequence de materiaux dielectriques et magnetiques anisotropes a l'etat solide et d'une epaisseur inferieure a 1 mm ainsi que de couches avec leurs substrats. Une methode de caracterisation en guide rectangulaire dans le bande X (8. 2 - 12. 4 GHz) puis en bande Ka (26. 5 - 40 GHz) a ete mise en œuvre et a permis de determiner les proprietes dielectriques et magnetiques d'echantillons en structure multicouche. L'application de cette methode aux couches minces magnetiques elaborees au laboratoire DIOM nous a permis de mettre en evidence des effets non reciproques pour des couches de YIG (ferrite Grenat) d'epaisseur de l'ordre de 4aem. Enfin, la transposition de cette methode vers la bande Ka a ete validee dans le cas de materiaux dielectriques

Journal of Magnetism and Magnetic Materials, 2005

The paper defines, describes, and presents the “P” curves for micro-structural characterization o... more The paper defines, describes, and presents the “P” curves for micro-structural characterization of the complex fluids, complex powders, and complex solid matrix, having magnetic properties. P curves are the first derivative (relative to the magnetic field strength) of the hysteresis curves relative to the saturation magnetization. They offer the possibility to investigate live biological materials without sample extraction.

Journal De Physique Iv, 2005

ABSTRACT Le développement de composants passifs intégrés (isolateurs, circulateurs) dans le domai... more ABSTRACT Le développement de composants passifs intégrés (isolateurs, circulateurs) dans le domaine des hyperfréquences et en particulier pour les télécommunications constitue un enjeu essentiel pour les années futures. La réalisation de ces composants intégrés nécessite la réalisation et la caractérisation de couches minces ferrimagnétiques de quelques mu\mumum d'épaisseur. Les méthodes décrites jusqu'ici dans la littérature sont bien adaptées à la mesure de couches à perméabilité élevée. La boucle de mesure, entourant la couche magnétique avec son substrat, est sensible à la contribution des deux milieux. Nous proposons ici 02une technique de mesure inductive ne prenant en compte que les caractéristiques de la couche déposée où la boucle de mesure n'entoure que la couche. Cette technique a été validée à plus grande échelle, des mesures préliminaires ont été effectuées sur des couches minces d'hexaferrite de baryum et de grenat de fer et d'yttrium déposées par pulvérisation cathodique RF sur un substrat d'alumine. Ces mesures nous ont permis de détecter les différentes difficultés et sources d'erreurs.

Journal De Physique Iv, 2005

Page 1. J. Phys. IV France 124 (2005) 159–163 C EDP Sciences, Les Ulis DOI: 10.1051/jp4: 20051240... more Page 1. J. Phys. IV France 124 (2005) 159–163 C EDP Sciences, Les Ulis DOI: 10.1051/jp4: 2005124024b Élaboration de couches minces YIG par pulvérisation cathodique RF pour la réalisation de composants hyperfréquences intégrés T. Boudiar1, C. Nader1, Th. ...

Journal of Magnetism and Magnetic Materials, 2005

The development of passive components in the microwave range for telecommunication applications i... more The development of passive components in the microwave range for telecommunication applications is a major focus for the next years. Some microwave passive components (such as circulators, isolators, etc.) still use magnetic materials. It is then necessary to characterize the electromagnetic properties of such materials, their scattering behaviours and to eventually highlight a non-reciprocal propagation. A method for the dielectric and magnetic characterization of multilayer materials in the X-band (8.2-12.4 GHz) is presented as well as its reliability and its domain of validity. It allows to determine the elements of the permeability tensor of ferrite sample. r

Physica Status Solidi (c), 2004

The paper takes into consideration the inductive transducers with magnetic fluids for inclination... more The paper takes into consideration the inductive transducers with magnetic fluids for inclination and aerodynamic measurements. Using their functional principle, we built flow rate transducers and flow meters for gases. In a N+1 flow meters network for gases controlled by computer, every N flow meters of closed range are supervised by another flow meter of higher range. The software of this structure can warn about any gases leakage in the network. Starting from the characteristics of the magnetic fluids transducers, the paper investigates the influence of the sensors reply time to the accuracy of measurements and to the possibility of detecting the gases leakage in the network. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Journal De Physique Iv, 2005

ABSTRACT Some microwave passive components (such as circulators, isolators, ... etc) still use b... more ABSTRACT Some microwave passive components (such as circulators, isolators, ... etc) still use bulk magnetic materials. A method for the dielectric and magnetic characterization of multi-layer materials in the microwave range is presented as well as its reliability and its domain of validity. It allows to determine the elements of the permeability tensor of gyromagnetic slab. This method of material characterization can be implemented at various microwave bands by changing the geometrical dimensions of the rectangular waveguide.

J Phys Iv, 2005

Some microwave passive components (such as circulators, isolators, ... etc) still use bulk magne... more Some microwave passive components (such as circulators, isolators, ... etc) still use bulk magnetic materials. A method for the dielectric and magnetic characterization of multi-layer materials in the microwave range is presented as well as its reliability and its domain of validity. It allows to determine the elements of the permeability tensor of gyromagnetic slab. This method of material characterization can be implemented at various microwave bands by changing the geometrical dimensions of the rectangular waveguide.

HAL (Le Centre pour la Communication Scientifique Directe), May 7, 2008

International audienc

Le developpement des systemes de telecommunications et de detection dans le domaine des hyperfreq... more Le developpement des systemes de telecommunications et de detection dans le domaine des hyperfrequences necessite la miniaturisation et l'integration de composants passifs micro-ondes. Le Laboratoire Dispositifs et Instrumentations en Optoelectronique et Micro-ondes (DIOM) s'est oriente vers la fabrication de couches minces magnetiques sur des substrats dielectriques d'epaisseur inferieure a 1 mm, dont l'objectif est la realisation de composants passifs miniatures qui doivent fonctionner au dela de 1 GHz. La connaissance des proprietes electromagnetiques du materiau utilise permet de fournir les elements essentiels a la modelisation de ce materiau en vue d'une simulation complete du composant. L'objectif de cette these est la caracterisation hyperfrequence de materiaux dielectriques et magnetiques anisotropes a l'etat solide et d'une epaisseur inferieure a 1 mm ainsi que de couches avec leurs substrats. Une methode de caracterisation en guide rectangulaire dans le bande X (8. 2 - 12. 4 GHz) puis en bande Ka (26. 5 - 40 GHz) a ete mise en œuvre et a permis de determiner les proprietes dielectriques et magnetiques d'echantillons en structure multicouche. L'application de cette methode aux couches minces magnetiques elaborees au laboratoire DIOM nous a permis de mettre en evidence des effets non reciproques pour des couches de YIG (ferrite Grenat) d'epaisseur de l'ordre de 4aem. Enfin, la transposition de cette methode vers la bande Ka a ete validee dans le cas de materiaux dielectriques

International Journal of Applied Electromagnetics and Mechanics, 2008

The paper investigates the numerical calculation of the electrical coils belonging to the inducti... more The paper investigates the numerical calculation of the electrical coils belonging to the inductive transducers with magnetic fluids for inclinations and aerodynamic measurements. One way to improve the construction of these transducers is to increase the electrical frequency for their coils. In this case, the thickness of the coils can be reduced by a large amount. The paper presents a numerical model for calculating the inductance of these ultra thin coils versus the level of the magnetic fluid core, the geometrical dimensions, and the magnetic properties of materials.

Progress In Electromagnetics Research C, 2011

Progress In Electromagnetics Research M, 2011

We propose a metamaterial coplanar stop-band filter made of multi-turn rectangular spiral particl... more We propose a metamaterial coplanar stop-band filter made of multi-turn rectangular spiral particles. Numerical and experimental results show the feasibility of devices with dimensions more than 10 times smaller than those in the literature and with good performances.

EPJ Web of Conferences, 2014

In telecommunication systems, heavy bulky magnets are used to establish the proper functioning of... more In telecommunication systems, heavy bulky magnets are used to establish the proper functioning of a circulator by ensuring the uniform orientation of the ferrite material's magnetic moment. Thus to develop an unbiased coplanar microwave circulator, the approach based on "ferromagnetic nanowired composite substrates" was promising. The idea was to do a magnetophoretic deposition of nanocoloidal cobalt ferrite nanoparticles into porous alumina membranes and permanently orient them uniformly. Therefore, in order to check the orientation possibility of the nanoparticle, samples of magnetic thin films on glass substrates were synthetized from CoFe 2 O 4 nanoparticles dispersed in a silica sol-gel matrix using the dip-coating technique with and without a uniformly applied magnetic field. To investigate the magnetic behavior of the prepared samples, the Faraday rotation as a function of the applied magnetic field was measured using a spectral polarimeter. The unambiguous qualitative difference between the Faraday rotation hysteresis loops shows a large variation of coercive (μ 0 H c) and remanent field () values, thus proving the orientation of the nanoparticles. Such nanocomposite is a promising candidate for future miniature microwave circulators fabrication.

Advanced Materials Research, 2011

A microstrip bandpass filter with rectangular patch coupled resonator is presented. The filter is... more A microstrip bandpass filter with rectangular patch coupled resonator is presented. The filter is designed to be more affected by the dielectric layer above the conductors compared to the same type of parallel-coupled bandpass filter. The filter is designed to operate between 1 GHz to 3 GHz and this can be a sensor base on distributed capacitors. The agreement between the circuit simulator and measured results is excellent and gives a very good prediction for the filter characteristics. The aim of this prototype filter is to show insertion loss (IL) at the bandpass transmission response when a dielectric material is above or near the conductors. A large study around the sensibility and the effect of the dielectric layer is done in order to evaluate its performance in detection and dielectric characterization.

Advanced Materials Research, 2011

in this paper, we propose a new multi-band patch antenna structure for embedded RFID (Radio Frequ... more in this paper, we propose a new multi-band patch antenna structure for embedded RFID (Radio Frequency Identification) readers and wireless communications. The proposed antenna is a dual band microstrip patch antenna using U-slot geometry. The operating frequencies of the proposed antenna are chosen as 2.4 and 0.9 (GHz), obtained by optimizing the physical dimensions of the U-slot. Several parameters have been investigated using Ansoft Designer software. The antenna is fed through a quarter wavelength transformer for impedance matching. An additional layer of alumina is added above the surface of the conductors to increase the performance of the antenna.

Http Www Theses Fr, 2004

Le developpement des systemes de telecommunications et de detection dans le domaine des hyperfreq... more Le developpement des systemes de telecommunications et de detection dans le domaine des hyperfrequences necessite la miniaturisation et l'integration de composants passifs micro-ondes. Le Laboratoire Dispositifs et Instrumentations en Optoelectronique et Micro-ondes (DIOM) s'est oriente vers la fabrication de couches minces magnetiques sur des substrats dielectriques d'epaisseur inferieure a 1 mm, dont l'objectif est la realisation de composants passifs miniatures qui doivent fonctionner au dela de 1 GHz. La connaissance des proprietes electromagnetiques du materiau utilise permet de fournir les elements essentiels a la modelisation de ce materiau en vue d'une simulation complete du composant. L'objectif de cette these est la caracterisation hyperfrequence de materiaux dielectriques et magnetiques anisotropes a l'etat solide et d'une epaisseur inferieure a 1 mm ainsi que de couches avec leurs substrats. Une methode de caracterisation en guide rectangulaire dans le bande X (8. 2 - 12. 4 GHz) puis en bande Ka (26. 5 - 40 GHz) a ete mise en œuvre et a permis de determiner les proprietes dielectriques et magnetiques d'echantillons en structure multicouche. L'application de cette methode aux couches minces magnetiques elaborees au laboratoire DIOM nous a permis de mettre en evidence des effets non reciproques pour des couches de YIG (ferrite Grenat) d'epaisseur de l'ordre de 4aem. Enfin, la transposition de cette methode vers la bande Ka a ete validee dans le cas de materiaux dielectriques

Journal of Magnetism and Magnetic Materials, 2005

The paper defines, describes, and presents the “P” curves for micro-structural characterization o... more The paper defines, describes, and presents the “P” curves for micro-structural characterization of the complex fluids, complex powders, and complex solid matrix, having magnetic properties. P curves are the first derivative (relative to the magnetic field strength) of the hysteresis curves relative to the saturation magnetization. They offer the possibility to investigate live biological materials without sample extraction.

Journal De Physique Iv, 2005

ABSTRACT Le développement de composants passifs intégrés (isolateurs, circulateurs) dans le domai... more ABSTRACT Le développement de composants passifs intégrés (isolateurs, circulateurs) dans le domaine des hyperfréquences et en particulier pour les télécommunications constitue un enjeu essentiel pour les années futures. La réalisation de ces composants intégrés nécessite la réalisation et la caractérisation de couches minces ferrimagnétiques de quelques mu\mumum d'épaisseur. Les méthodes décrites jusqu'ici dans la littérature sont bien adaptées à la mesure de couches à perméabilité élevée. La boucle de mesure, entourant la couche magnétique avec son substrat, est sensible à la contribution des deux milieux. Nous proposons ici 02une technique de mesure inductive ne prenant en compte que les caractéristiques de la couche déposée où la boucle de mesure n'entoure que la couche. Cette technique a été validée à plus grande échelle, des mesures préliminaires ont été effectuées sur des couches minces d'hexaferrite de baryum et de grenat de fer et d'yttrium déposées par pulvérisation cathodique RF sur un substrat d'alumine. Ces mesures nous ont permis de détecter les différentes difficultés et sources d'erreurs.

Journal De Physique Iv, 2005

Page 1. J. Phys. IV France 124 (2005) 159–163 C EDP Sciences, Les Ulis DOI: 10.1051/jp4: 20051240... more Page 1. J. Phys. IV France 124 (2005) 159–163 C EDP Sciences, Les Ulis DOI: 10.1051/jp4: 2005124024b Élaboration de couches minces YIG par pulvérisation cathodique RF pour la réalisation de composants hyperfréquences intégrés T. Boudiar1, C. Nader1, Th. ...

Journal of Magnetism and Magnetic Materials, 2005

The development of passive components in the microwave range for telecommunication applications i... more The development of passive components in the microwave range for telecommunication applications is a major focus for the next years. Some microwave passive components (such as circulators, isolators, etc.) still use magnetic materials. It is then necessary to characterize the electromagnetic properties of such materials, their scattering behaviours and to eventually highlight a non-reciprocal propagation. A method for the dielectric and magnetic characterization of multilayer materials in the X-band (8.2-12.4 GHz) is presented as well as its reliability and its domain of validity. It allows to determine the elements of the permeability tensor of ferrite sample. r

Physica Status Solidi (c), 2004

The paper takes into consideration the inductive transducers with magnetic fluids for inclination... more The paper takes into consideration the inductive transducers with magnetic fluids for inclination and aerodynamic measurements. Using their functional principle, we built flow rate transducers and flow meters for gases. In a N+1 flow meters network for gases controlled by computer, every N flow meters of closed range are supervised by another flow meter of higher range. The software of this structure can warn about any gases leakage in the network. Starting from the characteristics of the magnetic fluids transducers, the paper investigates the influence of the sensors reply time to the accuracy of measurements and to the possibility of detecting the gases leakage in the network. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Journal De Physique Iv, 2005

ABSTRACT Some microwave passive components (such as circulators, isolators, ... etc) still use b... more ABSTRACT Some microwave passive components (such as circulators, isolators, ... etc) still use bulk magnetic materials. A method for the dielectric and magnetic characterization of multi-layer materials in the microwave range is presented as well as its reliability and its domain of validity. It allows to determine the elements of the permeability tensor of gyromagnetic slab. This method of material characterization can be implemented at various microwave bands by changing the geometrical dimensions of the rectangular waveguide.