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Long-Term Drift of a Bandgap Voltage Reference by Molding Compound Oxidation during Extended Thermal Aging
No full text#81International audienceLifetime assessments only based on silicon wear-out mechanisms are insufficient to explain electricalparameter drifts of devices aged at high temperatures for long durations. This complexifies predictions forsemiconductor device aging. An alternative approach has been adopted in this study to explain these electricaldrifts, by considering the interaction of the silicon and its encapsulation. Specifically, this analysis is performedon a degraded Bandgap Voltage Reference circuit embedded in an encapsulated Integrated Circuit, previouslyaged during High Temperature Operating Life test conditions for 6500 h at a junction temperature of 165 °C. Agedsamples showed oxidized and deformed packages, that can explain the electrical parameter drift measured in thecircuit as recovery was observed after samples decapsulation. This is explained by reduced interaction betweensilicon and packag
Stability analysis and design of an event-triggered control scheme for a coupled ODE-heat PDE system. ⋆
No full textInternational audienceThis paper tackles the stability analysis of a system driven by linear ordinary differential equation coupled to a one-dimensional heat equation. The particularity of this study concerns the nature of the coupling, which is performed using an event-triggered scheme, through a boundary condition of the partial differential equation. After proving the existence and regularity of solutions of the system, the idea is to introduce an enriched energy functional as a candidate Lyapunov functional to prove the exponential stability. Actually, we will obtain a sufficient stability condition expressed as a linear matrix inequality to satisfy. This condition is suitable for solving an emulation problem corresponding to the appropriate tuning of the event-triggered control. Our result is finally illustrated with a numerical example
Mesures µ-OBIC sur diode bipolaire Diamant : une première !
No full textInternational audienceCette communication décrit pour la première fois la réalisation d'une diode bipolaire verticale en diamant qui présente des caractéristiques I(V) en direct et en inverse, pouvant donner lieu à des mesures micro-OBIC. L'OBIC est une technique de caractérisation spécifique permettant d'obtenir une image du champ électrique au sein d'un composant et ainsi d'analyser l'efficacité de ses protections périphériques
Fast detection of EMC level drifts induced by aging using biased thermal step stress : Application to an AC input EMC filter
No full textThis paper received second prize in the Song-Tsuen Peng Best Student Paper Award competition at APEMC 2025 symposiumInternational audienceThis paper presents the use of step stress accelerated aging tests associated with VNA measurements to efficiently detect the risk of potential EMC level drifts. The method is applied to an AC input EMC filter and a deviation in common mode attenuation is observed. Key points ensuring the validity of the results are discussed. Perspectives and limits are presented
Wirelessly Powered Battery-Free Sensing Nodes for Internet of Things Applications
No full textInternational audienceTheir quest to understand and control the world, humans seek to instrument their environments. Despite the diversity of technical solutions invented to date, there is still the problem of the reliable deployment of these solutions, whether in terms of volume, cost, or sustainability. To date, the most usable solutions to monitor and control physical phenomena in any environment are based on electronic systems, which require an electrical power supply
Reconstruction de fumée à partir d'images avec des primitives Gaussiennes volumétriques
No full textInternational audienceReconstruction de fumée à partir d'images avec des primitives Gaussiennes volumétrique
Méthodes approchées pour le partage de livraisons dans les circuits courts alimentaires
No full textInternational audienc
Wideband Tunable Filter of Dual-path Microstrip Coupled-lines with Varactor Tuned Circuit
No full textInternational audienceThis study presents a compact and tunable microstrip of dual-path wideband filter that employs coupled-lines and varactors to address the needs of 4G/sub-6 GHz 5G communication systems. This work integrates tunable methods inspired by wideband parallel coupled line-based topologies to realize a reconfigurable solution achieving a 34% frequency tuning range (1.13-1.51 GHz) while maintaining a low insertion loss of approximately below 1 dB. Specifically, the proposed microstrip-based filter, which is designed, uses parallel coupled-line resonators with a quarter-wavelength length, enabling a broad tuning range between 1.27-1.54 GHz. Adjusting the coupling strengths of both adjacent and non-adjacent resonators, the filter can be shifted within this frequency band without compromising performance. Therefore, to achieve the desired level of control, two identical varactor diodes and biasing circuitry are meticulously selected for their stable and repeatable capacitance-voltage characteristics to adjust the filter's resonant frequency. The optimal positions for these tuning circuits are determined based on the resulting capacitance, which is crucial for achieving a wide tuning range. Simulation and measurement confirm that this reconfigurable microstrip filter, implemented on a 60.7 × 35.4 mm 2 footprint, benefits not only from a reduced footprint but also from the ability to target multiple frequency bands with minimal hardware modifications, delivering the intended performance for modern wireless front ends
The dependence of the amino acid backbone conformation on the translated synonymous codon is not statistically significant
No full textInternational audienceThe correlation between synonymous codon usage and secondary structure in translated proteins has been widely demonstrated. This usage plays a capital role in tuning translational rates and protein folding kinetics, indirectly influencing multiple biological processes. A recent report [A. A. Rosenberg, A. Marx, A. M. Bronstein, Nat. Commun. 13 , 2815 (2022).] suggests that the translated synonymous codon influences the ( ϕ , ψ ) dihedral angles within secondary structure elements. If true, this conclusion would have strong consequences in several scientific fields, including structural biology and protein design, where results would depend on DNA sequence rather than protein sequence. Here, we show that the original statistical methodology used in the referred study was formally incorrect. Furthermore, when using a correct approach, we demonstrate that the influence of the codon on the distribution of the dihedral angles is not statistically significant for any type of secondary structure
Programmable metasurfaces for future photonic artificial intelligence
No full textInternational audiencePhotonic neural networks (PNNs), which share the inherent benefits of photonic systems, such as high parallelism and low power consumption, could challenge traditional digital neural networks in terms of energy efficiency, latency and throughput. However, producing scalable photonic artificial intelligence (AI) solutions remains challenging. To make photonic AI models viable, the scalability problem needs to be solved. Large optical AI models implemented on PNNs are only commercially feasible if the advantages of optical computation outweigh the cost of their input-output overhead. In this Perspective, we discuss how field-programmable metasurface technology may become a key hardware ingredient in achieving scalable photonic AI accelerators and how it can compete with current digital electronic technologies. Programmability or reconfigurability is a pivotal component for PNN hardware, enabling in situ training and accommodating non-stationary use cases that require fine-tuning or transfer learning. Co-integration with electronics, 3D stacking and large-scale manufacturing of metasurfaces would significantly improve PNN scalability and functionalities. Programmable metasurfaces could address some of the current challenges that PNNs face and enable next-generation photonic AI technology