The integration of wireless communication, e.g., in real- or quasi-real-time applications, is related to many challenges such as energy consumption, communication range, quality of service, and reliability. The improvement of wireless sensor networks (WSN) performance starts by enhancing the capabilities of each sensor node. To minimize latencies without increasing energy consumption, wake-up receiver (WuRx) nodes have been introduced in recent works since they can be always-on or power-gated with short latencies by a power consumption in the range of some microwatts. Compared to standard receiver technologies, they are usually characterized by drawbacks in terms of sensitivity. To overcome the limitation of the sensitivity ofWuRxs, a design of a low noise amplifier (LNA) with several design specifications is required. The challenging task of the LNA design is to provide equitable trade-off performances such as gain, power consumption, the noise figure, stability, linearity, and impedance matching. The design of fast settling LNA for a duty-cycled WuRx front-end operating at a 868 MHz frequency band is investigated in this work. The paper details the trade-offs between design challenges and illustrates practical considerations for the simulation and implementation of a radio frequency (RF) circuit. The implemented LNA competes with many commercialized designs where it reaches single-stage 12 dB gain at a 1.8 V voltage supply and consumes only a 1.6 mA current. The obtained results could be made tunable by working with off-the-shelf components for different wake-up based application exigencies.

Par rapport aux exigences de plus en plus importantes relatives au Maintien en Condition Opérationnelle d'un système industriel, le processus de maintenance joue un rôle fondamental pour l'amélioration de la disponibilité, de la productivité, etc. Pour essayer de contrôler au mieux ces performances, les responsables de maintenance doivent donc être capables de choisir les stratégies de maintenance et les ressources à mettre en oeuvre les plus adaptées aux besoins. Dans un objectif d'aide à la prise de décisions en maintenance, les travaux présentés dans ce mémoire ont pour objet de proposer une méthodologie pour l'élaboration d'un modèle support permettant par simulation d'évaluer les différentes stratégies. La valeur ajoutée de la méthodologie réside dans l'unification, à base de modèles relationnels probabilistes (PRM), des différents types de connaissance nécessaires à la construction de ce modèle d'évaluation. Ce dernier est ainsi construit à partir de motifs génériques et modulables représentatifs des variables décisionnels du système industriel (système principal) et de son système de maintenance. Ces motifs, par instanciation, facilitent la construction des modèles d'applications spécifiques. Cette méthodologie, issue du projet ANR SKOOB, est testée sur le cas applicatif de la maintenance d'un système de production de ferment. / Nowadays, the importance of the maintenance function has increased, due to the requirements on the maintain in operational conditions phase (MCO) of the system-of-interest (SI). As well as for the relevant role of maintenance in improving availability, performance efficiency, total plant availability, etc. To control performances, maintenance managers should be able to make some choices about the maintenance strategies and the resources that can fulfil the requirements. Within this context, we propose a methodology to formalize a model allowing to perform simulation to assess maintenance strategies. The scientific contribution of our work is that this approach unify by using a probabilistic relational model (PRM), different kind of knowledge needed to assess maintenance strategies. Knowledge is presented as generic and modular patterns based on PRM. These patterns integrate relevant decisional variables of the system of interest and of its maintenance system. This approach eases the modeling phase for a specific application. This methodology is one of the results of the project ANR SKOOB. This approach was tested on an industrial case for the maintenance of a harvest production process