The objective of this paper is to carry out periodic orbital propagation and bifurcations detection around asteroid 433 Eros. Specifically, we propose to exploit a frequency-domain method, the harmonic balance method, as an efficient alternative to the usual time integration. The stability and bifurcations of the periodic orbits are also assessed thanks to the Floquet exponents. Numerous periodic orbits are found with various periods and shapes. Different bifurcations, including period doubling, tangent, real saddle and Neimark-Sacker bifurcations, are encountered during the continuation process. Resonance phenomena are highlighted as well.

In this paper, some theoretical aspects and experimental results are discussed with the aim to provide supplementary dc energy to radio frequency identification (RFID) tags by exploiting the nonlinear nature of rectifier devices. Three nonlinear phenomena are treated: (i) the impedance power dependence, (ii) the harmonic production, and (iii) the dependence on the radio frequency waveform. The novelty of the work relies on proposing a double rectifier composite system in where the nonlinearity of each rectifier is exploited to enhance the global powering performance of the system. Using the passive RFID technology as a beacon for the implementation, the approach considers combining the internal rectifier circuit of a commercial RFID chip operating at 868 MHz with an external rectifier circuit operating at 2.17 GHz. The solution triggers in a composite system RFID tag-harvester integrated in a single-feed dual-band antenna. The experimental validation shows 5 dB of tag sensitivity enhancement when it is empowered by the external harvester. The enhanced sensitivity produces an increase in the theoretical reading range distance from 3.3 to 6.1 m.

This paper discusses novel methodologies for the characterization of harmonic signals generated by wireless powered devices, i.e. passive ultra-high frequency (UHF) radio frequency identification (RFID) tags, due to the wireless power transferred from reader to tag. Theoretical aspects, as well as measurements to characterize these non-linear phenomena are exposed. Particular care is taken to explain the analysis methodology and setup for two kinds of characterization measurements: radiated and conducted. The existence of harmonic signals carrying information is exploited in an advanced application example. A dual-band RFID tag is designed to increase the backscattered harmonic level in the tag-to-reader link. Measurement of this dual band tag demonstrates the exploitation of the hitherto neglected harmonic power; it also opens the door to more advanced applications exploiting the harmonic-link communication.

A detailed nonlinear analysis and design of a distributed voltage controlled oscillator (DVCO) is presented in this work. The analysis and design of the DVCO is performed using harmonic balance-based simulation techniques and envelope transient simulation. These techniques are used to make a complete nonlinear study of the behavior of the DVCO. Using the proposed nonlinear tools, a DVCO operating in the frequency tuning range between 1 and 2 GHz has been implemented in order to support the simulation results. The average output power and consumption along the frequency band for the designed DVCO are 5.2 dBm and 60.4 mW, respectively.

Dans cet article, nous présentons une méthodologie numérique pour l'analyse des vibrations non-linéaires des plaques sandwich constituées d'une couche viscoélastique intercalée entre deux parements élastiques. Les modèles de von Karman pour les couches élastiques et de Mindlin pour la couche viscoélastique ont été adoptés. Cette méthode est basée sur une discrétisation par éléments finis et la technique de la balance harmonique couplée à la méthode de Galerkin à un mode. Ainsi, les vibrations non-linéaires des plaques sandwich viscoélastiques ont été modélisées par une simple équation d'amplitude complexe, qui est obtenue par le calcul numérique de deux coefficients complexes. Le premier coefficient permet d'estimer l'amortissement et la fréquence dans le cas linéaire, tandis que le second rend compte des effets non-linéaires en grands déplacements. Les formulations de la pulsation et du facteur de perte en fonction de l'amplitude ont été données analytiquement.Pour valider ce modèle, le calcul numérique d'amortissement dans les cas linéaire et non-linéaire et les courbes de réponses pour différentes structures sandwich viscoélastiques (poutres, plaques) ont été présentés et favorablement comparés à des résultats de la littérature et de l'expérience.