Find here the list of publications
  • Note you need to register to check out.
  • Once registered, please go to the private section

If you are not registered, some of the most recent papers can be loaded from the IEEE or from ResearchGate

Electronic document not available, please consult the Workshop book.

This is the first time a MoM was ported on a PC with a graphical interface; This paper deals with results for the MAROTS satellite tested by MATRA-ESPACE under ESA contract at ITALTEL, Milano

Cet article illustre les nouvelles capacités d’une analyse instationnaire directe par la méthode des moments. On examine d’abord le formalisme mathématique qui permet d’aboutir à une solution itérative. Quelques exemples sont ensuite proposés, démontrant les capacités de cette nouvelle méthode à traiter les problèmes de diffraction. L’algorithme utilisé présente une bonne convergence, libre d’instabilités numériques et les avantages suivants:

– traitement des non-linéarités,

– accés à une large bande en fréquence à partir d’une simple analyse,

– interprétation aisée et adéquation aux phénomènes physiques (EMP, ESD, foudre, …)

– compatibilité avec les outils de CAO. et les programmes E.F.I.E. fréquentiels en méthode des moments .

Ce papier décrit le moyen permettant de représenter par MOM une ou plusieurs jonctions fil/surface à multiplicité élevée. Cette jonction est définie comme le point d’attachement de l’extrêmité d’un segment ou de plusieurs segments avec un des noeuds d’une surface maillée.C’est la raison pour laquelle la nouvelle fonction de base est appelée fonction vertex. Une attention toute particulière est portée sur les contraintescaractéristiques à ce type de jonction. Après une présentation du nouveau type de fonction de base et de son implémentation dans les logiciels MAXSIM-F (fréquentiel) et MAXSIM-T(Instationnaire) qui utilise une décomposition des  courants de type JPE (J Polynômial Edged functions), quelques exemplesdémontrent clairement sur des quantités sensibles   (impédance,champ proche) le bien fondé de la méthode..

Les stations de travail actuelles permettent d’étudier le comportement électromagnétique de systèmes de très grande taille. La montée en puissance des nouveaux calculateurs et leur capacité en mémoire vive de plus en plus importante permet d’aborder la résolution de problèmes système qu’il était, il y a quelques années encore impossible d’envisager. Les techniques numériques se sont adaptées à cette évolution et les méthodes intégrales présentent depuis quelques années un regain d’intérêt, aussi bien dans le domaine fréquentiel que temporel. Des sociétés se sont pourvues de telles techniques qui permettent de représenter fidélement un objet à partir des données de CAO, tout en apportant aux résultats une précision inégalée à ce jour.

L’objet de cette présentation est de démystifier les difficultés associées à la formulation du problème par méthode des moments. Une approche didactique de la méthode des moments est présentée pour le cas d’une structure filaire. Celui-ci est détaillé dans cette présentation pour le cas fréquentiel 

Des résultats de validation et l’application à des systèmes des outils MAXSIM-F et MAXSIM-T développés à MATRA-MARCONI sont présentés.

Les orientations futures sont ensuite passées en revue, notamment l’extension d’une telle méthode au problème des ouvertures et cavités ainsi que l’extension en très haute fréquence et l’aspect transitoire de la méthode des moments.

Usually, the Electric Field Integral Equation (EFIE) is solved under a Mixed Potential Integral Electric field equation (MPIE) to solve the scattering of surface/wire arbitrary shape placed in the vacuum. Using the Green’s function for the half-space, derived from the image theory, the capacities of the MOM solver can be significantly improved to model objects over one or more ground planes, to model apertures inside ground planes, …. Such examples are shown and constitute the transition to a more powerful method mixing various Green’s dyadics in the same problem. The extension to the waveguide and as a consequence to the rectangular cavity are theoretically investigated.

This paper focus on the numerical details for implementing in the MoM méthod curved surfaces joined with curved wires; The electronic document is not available. Please consult the conference document

An implicit time domain model for the analysis of wires and conducting surfaces is presented. The model is based on the method of moments numerical technique using lagrange second order time domain polynomial basis functions which plays an important role on the road to stability. With this type of formulation, the method of moments can be finally be utilized for the analysis of fast transients directly in the time domain for structures including wires and surfaces. The model’s stability and accuracy are presented for a complex system including conducting surfaces, transmission lines and non-linear loads.

Depuis quelques années, la méthode des moments (MoM) s’est révélée comme une méthode précise et extrêment flexible et robuste pour résoudre de nombreux problèmes de diffraction éléctromagnétique. Les limitations de cette méthode apparaissent clairement lorsque l’objet traité présente une grande taille devant la longueur d’onde. non pas pour des raisons mathématiques ou physiques, mais simplement du fait de la taille mémoire allouée au calculateur. Nous présentons dans cet article deux méthodes adaptées au traitement de ce problème. La première est une technique purement MoM basée sur une modification de la fonction de Green caractérisant le milieu environnant. La seconde est une méthode hybride basée sur une explicitation des courants à haute fréquence, principalement adaptée au domaine des antennes.

L’équation intégrale en champ électrique (EFIE) est la plupart du temps résolue sous la forme de potentiels mixtes (MPIE) afin de résoudre les problèmes de diffraction. La grande majorité de ce type de solveur fonctionne en supposant que l’objet est placé dans l’espace libre. Une modification simple de la fonction de Green permet de représenter un ou plusieurs plans de symétrie électrique (Plan de  masse)/magnétique (Plan de symétrie). Ceux-ci peuvent de plus supporter des courants magnétiques/électriques permettant de representer une ouverture (Plan de masse) ou un objet métallique (Dans le plan de symétrie)

L’implémentation de telles capacités est présentée pour le logiciel MAXSIM-F et constitue une transition importante vers des développements futurs combinant dans le même problème plusieurs zones topologiques couplées dont les conditions de rayonnement sont différentes (fonctions de Green).

We present in this paper an hybrid MoM tool named EMC2OOO. Its main objective is to work at higher frequency than conventional MoM methods. Several hybrid features have been linked with the original EFIE&MFIE MoM kernel.including:

    -apertures and slots in real objects (PMCHW),

   -wire & surface Huygens sources (J & M )

   – PO method combined with the iterative MFIE

   – Green’s function formalism for coupled cavities

   – domain decomposition technique

All these features are together compatible, hybrided with the MoM & self-consistent making EMC2OOO highly flexible and adapted for a large class of electromagnetic problems.

Ce papier décrit la méthodologie utilisée dans le logiciel EMC2000 pour traiter de manière générale le comportement électromagnétique d’ouvertures larges ou de fentes minces de forme quelconque dans un plan de masse ou sur un objet tridimentionnel de forme arbitraire ainsi que leur jonction fente/ouverture.

Les équations intégrales obtenues à partir du principe d’équivalence surfacique sont tout d’abord définies. On décrit ensuite la procédure numérique qui permet d’évaluer le rayonnement d’ouvertures ou de fentes excitées en présence d’un objet métallique soit par un champ incident soit par une antenne. Quelques exemples issus de la littérature et de mesure sont présentés. Un exemple de traitement de fente mince sera présenté interactivement en séance.

EMMC2000  is an hybrid tool merging various EM theories. The goal of this hybridation is to extend the capabilities of the tool, to reduce the memory requirement and to extend the frequency range of the present version.  Among the various possibilities are the combination of the EFIE with other EM numerical methods:

– (1) the MFIE (Magnetic Field Integral Equation) for closed surfaces

– (2) the PMCHW equations(from the name of the author who derived it) to treat consistently

the apertures in a ground plane or on a real scatterer

– (3) the equivalence principle (Love or generalized form)

– (4) the POHM (Physical Optic Hybrid Method)

– (5) the HEMI method (Hybrid EM Iterative)

 

Another very fruitfull topic is based on the Green’s dyadic method. In this document, we present the related backgrounds associated with the treatment of a closed rectangular cavity. The application in the context of the treatment of an arbitrary object located inside a rectangular cavity is presented ;

We present in this paper an hybrid MoM tool named EMC2OOO. Its main objective is to work at higher frequency than conventional MoM methods. Several hybrid features have been linked with the original EFIE&MFIE MoM kernel. including:

    – apertures and slots in real objects (PMCHW),

   – wire & surface Huygens sources (J & M )

   – PO method combined with the iterative MFIE

   – Green’s function formalism for coupled cavities

   – domain decomposition technique

All these features are together compatible, hybrided with the MoM & self-consistent making EMC2OOO highly flexible and adapted for a large class of electromagnetic problems.

During the presentation, all these features will be explained & followed with a real demonstration of  pertinent examples treated by the software .

Ce papier décrit la méthodologie utilisée dans le logiciel EMC2000 pour traiter de manière générale le comportement électromagnétique d’ouvertures larges ou de fentes minces de forme quelconque dans un plan de masse ou sur un objet tridimentionnel de forme arbitraire ainsi que leur jonction fente/ouverture.

Les équations intégrales obtenues à partir du principe d’équivalence surfacique sont tout d’abord définies. On décrit ensuite la procédure numérique qui permet d’évaluer le rayonnement d’ouvertures ou de fentes excitées en présence d’un objet métallique soit par un champ incident soit par une antenne. Quelques exemples issus de la littérature et de mesure sont présentés. Un exemple de traitement de fente mince sera présenté interactivement en séance.

In many situations, when solving an EM problem by means of the Method Of Moments (MoM), the size of the diffracting object or the frequency of interest is too high, so that the involved matrix exceeds the available disk or RAM memory. One of the remedy is to combine the MoM with an asymptotic method. We present in this paper a mixed method based on the current formulation. This one leads to a drastic reduction of the required memory at the expense of an approximation of the currents in zones where it is anticipated that the asymptotic behaviour of the currents is valid. Various asymptotic formulations of the currents exists. Among the most popular, one finds :

– the Physical Optics (PO), well suited for large planar surfaces

– the Fock currents for curved surfaces

– various corrections for edge, wedge, …

We present in this paper an adaptation of the EMC2000[1] software for the implementation of the physical optics. Comparison with available results are presented. An interactive demonstration with  computation on a MoM/PO example will be done on a PC during the presentation.

Because of the new challenges in aeronautics, electromagnetic(EM) modelling has become of high importance in the development of antenna placement, antenna new developments, EMC compatibility and protection against hazards (lightning, cellular phone, new threads, ..)

We present in this paper an overview of the numerical techniques that are used for electromagnetic applications in aerospace.  The various electromagnetic problems are first reviewed. Then we present briefly the various numerical techniques that allow to treat problems in specific situations.   Together with these numerical techniques, we focus on geometrical constrainsts in relation with each numerical technique. Some techniques need a minimal information (CAD information) while other’s one need a specific meshing with surfaces only (quads, trias, conformal elements) or volumes (bricks, tetrahedrals,…) and even properties to link with the meshed model.

Finally, an application linking an EM computation with the GID software is presented.

 

 This paper presents the various steps to build a MoM code when working in a rectangular cavity as boundary condition. Due to space considerations, this paper is splitted in 3 parts.

Part 1 focus on the Green’s function for a metallic box for electric currents only.  The convergence of the Green’s function out of the singularity zone (r#r’) and close to the singularity zone is reviewed with a specific attention for large size cavities with tricks to reduce the computational time and to increase the accuracy.

Part 2, to be published will focus on the treatment of the Green’s functions in the singularity zone with the Ewald method & results of Green’s function convergence for the calculation of the involved series.

Finally, Part 3 also to be published will cover  the implementation of the whole cavity Green’s function in a MoM code including arbitrary geometries made of triangular, wire & wire to surface junctions with treated examples.

This paper presents the various steps to build a MoM code when working in a rectangular cavity as boundary condition. Due to space considerations, this paper has splitted in 3 parts.

Part 1 have focused on the Green’s function for a metallic box for electric currents only.  The convergence of the Green’s function out of the singularity zone (r#r’) and close to the singularity zone is reviewed with a specific attention for large size cavities with tricks to reduce the computational time and to increase the accuracy.This paper was published in EUCAP2006-Nice (France)

The present paper focus on the treatment of the Green’s functions in the singularity zone with the Ewald method & results of Green’s function convergence for the calculation of the involved series.

Part 3 to be published will cover  the implementation of the whole cavity Green’s function in a MoM code including arbitrary geometries made of triangular, wire & wire to surface junctions with treated examples

This paper presents the various steps to build a MoM code when working in a rectangular cavity as boundary condition. Due to space considerations, this paper has splitted in 3 parts.

Part 1 have focused on the Green’s function for a metallic box for electric currents only.  The convergence of the Green’s function out of the singularity zone (r#r’) and close to the singularity zone is reviewed with a specific attention for large size cavities with tricks to reduce the computational time and to increase the accuracy.This paper was published in EUCAP2006-Nice (France)

The present paper focus on the treatment of the Green’s functions in the singularity zone with the Ewald method & results of Green’s function convergence for the calculation of the involved series.

Part 3 to be published will cover  the implementation of the whole cavity Green’s function in a MoM code including arbitrary geometries made of triangular, wire & wire to surface junctions with treated examples

With the advent of faster computers and accelerated methods, numerical modellingtechniques have become increasingly suitable for the design and verification of antenna installations on aircraft, but it is necessary to validate their performance. In this paper we report on comparisons made between calculations and measurements of antenna radiation patterns performed on an 1/18th scale model of a generic single aisle passenger jet. Two types of antenna were considered: VHF blade antennas (to verify the validity of an equivalent model of a complex antenna structure) and Air Traffic Control (ATC) antennas (to check the validity at higher frequencies). Very good comparisons were obtained between measurements and calculations when one simulates the details of the measurements

We present a new, easy to use, simulator of the Instrument Landing System. The Method of Moments (MoM) and the MultiLevel Fast Multipole Method (MLFMM) allow precise predictions of perturbations due to buildings, taxiing aircraft and other scatterers encountered in an airport environment.

We present a new, easy to use, simulator of the Instrument Landing System. The Method of Moments (MoM) and the MultiLevel Fast Multipole Method (MLFMM) allow precise predictions of perturbations due to buildings, taxiing aircraft and other scatterers encountered in an airport environment.

The recent ILS localiser prediction tool, ATOLL, has been employed to study a range of different scenarios. Simulations produce similar results to measurements performed on a glideslope mast and a taxiing Airbus A380 aircraft. A study on simple rudder-sized plates demonstrates the limits of the PO method. Simulations performed on cranes show a strong dependence upon the angle of the jib. The effects of multiple inter-crane interactions are seen to been insignificant for these geometries..

We present a solution to the problem of ILS disturbance due to an aircraft hangar to be constructed at Toulouse International Airport, France. Before construction, the problem is analysed with the full-wave ILS simulator `ELISE’. A solution in the form of a diffraction grating is then proposed, optimized and re-simulated with ELISE. Simulations demonstrate that the proposed solution easily satisfies the CAT3 criteria. The construction of the building has begun (mid December 2011) and the diffraction gratings will be installed in the Summer. At the time of writing we await confirmation of patens that we have filed concerning more compact structures that we will present during the conference.

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut elit tellus, luctus nec ullamcorper mattis, pulvinar dapibus leo.

In this article, we present work being performed at Airbus Group Innovations (AGI), the research center of the Airbus Group, in the area of building stealth. Building restrictions relating to perturbations of aircraft landing systems prevent several tens of square kilometers of land within and close to airports from being used for construction. We present techniques that allow these perturbations to be characterized by numerical simulation and corrected by the placement of specially devised panels, producing a diffraction grating. Examples illustrate a classic thick diffraction grating implanted on a building at Toulouse International Airport in France, and a recently developed thin diffraction grating.