Optical diffraction of fractal figures: random Sierpinski carpets

The optical diffraction patterns of random Sierpinski carpets of different fractal dimensions at different levels of iteration are shown and analyzed. The sensitivity of such an analysis to long range correlations, is demonstrated theoretically by means of the transfer matrix formalism of fractals, T.M.F. The relation between the subdimensions defined in T.M.F. and diffraction patterns is outlined. Finally an analysis of experimental diffraction patterns is proposed in order to measure these new theoretical subdimensions.On présente ici les clichés de diffraction optique de tapis de Sierpinski aléatoires de différentes dimensions fractales, pris à des niveaux d'itération différents. Au moyen du formalisme de la matrice de transfert dans les fractals, on montre la sensibilité de cette analyse expérimentale aux corrélations à moyenne et longue portée. Ainsi la relation entre les sous-dimensions fractales du F.M.T. et les rapports d'intensité entre les clichés de diffraction de figures fractales à des niveaux d'itération différents est soulignée. Enfin on esquisse le principe d'une analyse expérimentale de ces nouvelles dimensions théoriques

Integrated saw filter into a silicon passive integration connecting substrate

International audienc

A SAW filter integrated on a silicon passive substrate used for system in package

International audienceA packaging method for dies containing an electro-mechanical component on a silicon substrate with a polymer seal ring is described in this paper. A Surface Acoustic Wave (SAW) filter, which is a kind of Micro Electro-Mechanical System (MEMS), is used as a capping substrate. Two different polymers are tested, Benzocyclobutene (BCB) and SU-8. The polymer and the assembly processes are described. The package has been characterized mechanically and the influence of the package on the electrical operation of the filter has been evaluated. A finite element thermo-mechanical analysis has been performed to simulate and understand the behaviour of this heterogeneous flip-chip package. This package enables to decrease the size of the assembly around 50% in term of thickness and footprint area without any electrical degradation compared to a stand-alone component

FEM/BEM Analysis for SAW devices

paper 3a2 (18 pages) on proceedings CD-ROMInternational audienc

High-Frequency Surface Acoustic Wave Devices Based on Epitaxial Z-LiNbO3 Layers on Sapphire

International audienceFilter market demand pushes to the development of new piezoelectric materials to address modern telecommunication challenges. Composite wafers combining an epitaxial piezoelectric layer and a said high velocity and acoustic quality substrate is a promising way to answer that demand. However, the fabrication of high-quality LiNbO3 films with reproducible physical properties is complicated by the difficulty to control volatile Li2O incorporation into the film and to measure its composition. So far, large-scale production of films with physical properties suitable for the targeted applications is not available. In this paper, lithium niobate films with controlled nonstoichiometry were deposited by means of pulsed injection metalorganic vapor phase deposition. We have demonstrated a high acoustical performance for surface acoustic wave (SAW) devices operating in the frequency range from 3.7 GHz up to 5.3 GHz and based on grown epitaxial Z-axis oriented LiNbO3 films on sapphire. An electromechanical coupling of 8 % for the Rayleigh wave at 5.3 GHz was demonstrated experimentall