Modeling of a compact, implantable, dual-band antenna for biomedical applications

Different implantable antenna designs exist to establish communication with implantable devices depending on the domain of use and the implantation space. Owing to their nature and purposes, these antennas have many imposed criteria on various characteristics, such as bandwidth, multiband behavior, radiation pattern, gain, and specific absorption rate (SAR). This presents a challenge when it comes to achieving satisfying results without a major compromise in any of these crucial parameters. Additionally, many of the existing designs do not follow a specific approach to obtain results. Measuring different parameters of such fabricated structures requires special conditions and special environments mimicking the tissues where they are supposed to be placed. For such issues, the use of biological or synthetic phantoms is widely employed to validate what is obtained in simulation, and a multitude of formulas exist for the creation of such phantoms, each with its advantages and drawbacks. In this paper, a miniature dual-band structure derived from the first iteration of the Koch fractal structure is designed to operate 2 mm below the skin in the arm of the human body, with the MICS (Medical Implant Communication System) and ISM (Industrial, Scientific, Medical) 2.4 GHz bands. The purposes of the design are to derive structures from commonly used shapes with certain behavior while maintaining miniaturization, and to easily design dual-band implantable antennas. More than one band is used to diversify uses, since bands such as the MICS band are mainly dedicated to telemetry. The structure is characterized not only by its low profile compared to various structures found in the literature with dimensions of 17.2 × 14.8 × 0.254 mm3, but also its ease of design, independent shifting of resonant frequencies, and the absence of the need for a matching circuit and a shorting pin (via) for miniaturization. It exhibits satisfying performance: bandwidths of 23 MHz in the MICS band and 190 and 70 MHz in the vicinity of the ISM 2.4 GHz band, and measured gain in the latter band of −18.66 and −17 dBi in the azimuth and elevation radiation patterns, respectively. To validate the antenna’s properties in a skin-mimicking environment, two simple phantom formulas found in the literature were explored and compared in order to identify the best option in terms of accuracy and ease of fabrication.The authors would like to thank Nicolas Corrao for his tremendous effortsthroughout the challenging fabrication process of the preliminary models at the HYPER platform,IMEP-LaHC, University of Grenoble Alpes. R. Silva would like to thank FCT for grant 2021.06819.BD.All individuals included in this section have consented to the acknowledgement

Enseignement du numérique : Les apports d'un Learning Lab

National audienceDans cette communication, nous décrivons les évolutions de l’apprentissage liées à l’apport du numérique. Parmi ces évolutions, on voit apparaître de nouveaux lieux de formation appelés « learning labs ». L’objectif de cet article est de présenter comment la mise en œuvre d’un tel lieu (on parle aussi de tiers-lieu) offre de nouvelles perspectives, modifie la manière d’enseigner et donne des résultats intéressants à la fois pour les enseignants (en terme d’évaluation des savoirs et des savoir-faire) et pour les apprenants (en terme de motivation, d’immersion et d’échanges). Dans un second temps, nous nous focaliserons sur la place prépondérante que peut prendre l’électronique dans la mise en place de nouvelles formations, notamment autour des objets connectés. Nous illustrerons concrètement notre propos autour d’une formation expérimentale qui a obtenu le label GEN (Grande Ecole du Numérique

Méthode robuste d’extraction de paramètres de ligne de transmission en vue d’application à la caractérisation de matériaux

National audienc

Propriétés diélectriques de films BST jusqu'à 110 GHz : applications aux varactors en bandes millimétriques

National audienc

Propriétés diélectriques de films BST jusqu'à 110 GHz : applications aux varactors en bandes millimétriques

National audienc

Propriétés diélectriques de films BST jusqu'à 110 GHz : applications aux varactors en bandes millimétriques

National audienc

Characterization of ferroelectric films up to 60 GHz : application to phase shifters

International audienceParaelectric Ba0.5Sr0.5TiO3 films 0.3 μm thick have been deposited by sol-gel on c-axis sapphire substrates. They have been investigated from 1 kHz to 60 GHz using coplanar waveguide transmission lines and interdigitated capacitors. The dielectric constant εr is around 300 and the loss tangent is 0.16 at 50 GHz. The tunability is constant with frequency with a mean value of 42%. Analog phase shifters were subsequently fabricated. A 180° phase shift was obtained at 60 GHz with a 17 V bias. The maximum value of phase shift per decibel of insertion losses (at 0 V) is 13°/dB at 30 GHz with a bias of 30 V

Caractérisation in-situ jusqu'à 100 GHz d'isolants utilisés dans les nouvelles technologies 3D de type "System in Package on Board" (SiPoB)

International audienc

Caractérisation jusqu'à 9 GHz de solutions corrosives eau/bromure de lithium à l'aide d'un connecteur SMA faible coût

International audienc

InP composite substrate for low-cost high-end RF applications

International audienc