MacroModel based DG-FDTD for Calculating Local Dosimetry in a Variable and Highly Multiscale Problem

International audienceThis paper proposes a method to estimate human exposure to electromagnetic field radiation in a variable and highly multiscale problem. The electromagnetic field is computed using a combination of two methods: a rigorous time domain and multiscale method, the DG-FDTD (Dual Grid Finite Difference Time Domain) and a fast substitution model based on the use of transfer functions. The association of these methods is applied to simulate a scenario involving an antenna placed on a vehicle and a human body model located around it. The purpose is to assess the electromagnetic field in the left eye of the human body model. It is shown that this combination permits to analyse many different positions in a fast and accurate way

Combinaison de la DG-FDTD avec un modèle de substitution pour un calcul de dosimétrie locale dans un problème variable et fortement multiéchelle

Cet article propose une méthode d'estimation de l'exposition locale des personnes aux rayonnements électromagnétiques dans un problème variable et fortement multiéchelle. Le débit d'absorption spécifique est estimé grâce à l'association de deux méthodes. On propose ainsi la combinaison d'une méthode rigoureuse de simulation temporelle multiéchelle, la DG-FDTD (Dual Grid FDTD) avec un modèle de substitution basé sur le principe de superposition et l'utilisation de fonctions de transfert

Combination of DG-FDTD with a Substitution Model for Calculating Local Dosimetry in a Variable and Highly Multiscale Problem

International audienceThis paper proposes a method to estimate human exposure to electromagnetic field radiation in a variable and highly multiscale problem. The electromagnetic field is estimated using a combination of two methods: a rigorous time domain and multiscale method, the DG-FDTD (Dual Grid Finite Difference Time Domain) and a substitution model based on the superposi- tion principle and the use of transfer functions. The association of these methods is applied to simulate a scenario involving an antenna placed on a vehicle and a human body model located around it. The purpose is to assess the electromagnetic fields in the left eye of the human body model. It is shown that this combination permits to analyse many different positions in a fast and accurate way

An application of the Multi-Level DG-FDTD to the analysis of the transmission between a dipole in free space and an implanted antenna in a simplified body model with various positions

International audienceWe propose to use the advantages of the multi-level dual-grid finite-difference time domain (DG-FDTD) method to determine, in a short computation time, the transmission between an antenna implanted in a simplified homogeneous body model and a half-wavelength dipole (at 402 MHz) located in free space. The transmission coefficient is determined for four different positions of the body

Utilisation de la DG-FDTD pour un calcul de dosimétrie dans un problème fortement multiéchelle : détermination du DAS oeil pour une personne située à proximité d'une source HF/VHF embarquée sur un véhicule

National audienceLa dosimétrie consiste à l'évaluation de l'exposition des personnes aux rayonnements électromagnétiques. Au vue de la complexité du corps humain, la méthode la plus appropriée pour effectuer des simulations électromagnétiques est la méthode des différences finies dans le domaine temporel. Néanmoins, la FDTD pose certains problèmes dus notamment à un schéma de maillage uniforme qui peut rendre les simulations couteuses en ressources informatiques. Cette publication expose l'avancé de nos recherches sur la méthode intitulée DG-FDTD basée sur la division du problème global en sous-volume FDTD. Cette technique a pour but de caractériser chaque élément de l'environnement de simulation à l'aide d'un maillage approprié. L'exécution de la simulation est effectuée de manière séquentielle grâce à un transfert de l'information électromagnétique entre les différents volumes. Dans un premier temps, cette étude s'amorce sur la validation de la méthode DG-FDTD dans un problème simple. Dans un second temps, un scénario plus complexe est traité en utilisant cette méthode. Les résultats de cette simulation permettent de montrer l'efficacité de la DG-FDTD pour traiter des problèmes de dosimétrie fortement multiéchelles

Near-field data compression for the far-field computation in FDTD

This paper presents a technique to compress the near-field data required to compute the radiated fields using FDTD. This technique is applied to the study of a UWB planar diamond antenna. The results show a 99.8% gain in memory storage, while maintaining good accuracy: less than 1% error on the far-field radiation patterns

An Efficient Numerical Technique to Predict Phase Responses of Reconfigurable Reflectarray Cells with Mutual Coupling

International audienceThis paper presents a numerical technique to predict realistic phase responses of active cells within a reflectarray. The phase responses of an active cell are determined as a function of the states of the neighboring cells. The phase probability distributions are computed and realistic phase responses are then evaluated. A synthesis application is presented in order to highlight the interest of the realistic phase responses

Global technique analysis for reconfigurable reflectarray antennas

International audienceThis paper focuses on the simulation of reconfigurable reflectarrays. A new method combining the 'surrounded-cell' approach and the compression method is presented. The method considers the real environment of the radiated elements and it only requires one lightweight electromagnetic simulation for the whole reflectarray

Exposure Assessment Using the Dual-Grid Finite-Difference Time-Domain Method

A new way to carry out numerical cellular telephone simulation in the presence of the head is presented. Here, two finite-difference time-domain (FDTD) simulations with different spatial and time resolutions are sequentially combined to perform a dual-grid FDTD (DG-FDTD) simulation. The DG-FDTD approach has the significant advantages to remain stable along the computation and to be easy to implement in a typical FDTD code. When compared with classical FDTD analysis, the DG-FDTD approach exhibits a reduction in computation time and memory requirements by a factor of 2.3 and 3.2, respectively, while providing accurate results both in near-field and far-field radiation

Rigorous analysis of a satellite antenna including its surrounding environment with the Dual-Grid FDTD method

International audienceThis paper presents a rigorous analysis of a satellite antenna mounted onto its platform using the Dual-Grid FDTD method. In the first step of the method, the isolated antenna is analyzed. The study of the surrounded antenna is carried out in the second step of the DG-FDTD method. The results obtained in this realistic test case show the significant influence of the environment over the antenna