About Quartz Crystal Resonator Noise: Recent Study

The first step, before investigating physical origins of noise in resonators, is to investigate correlations between external measurement parameters and the resonator noise. Tests and measurements are mainly performed on an advanced phase noise measurement system, recently set up. The resonator noise is examined as a function of the sensitivity to the drive level, the temperature operating point and the tuning capacitor.Comment: 20th International Conference on Noise and Fluctuations, Pisa : Italie (2009

High-resolution microwave frequency dissemination on an 86-km urban optical link

We report the first demonstration of a long-distance ultra stable frequency dissemination in the microwave range. A 9.15 GHz signal is transferred through a 86-km urban optical link with a fractional frequency stability of 1.3x10-15 at 1 s integration time and below 10-18 at one day. The optical link phase noise compensation is performed with a round-trip method. To achieve such a result we implement light polarisation scrambling and dispersion compensation. This link outperforms all the previous radiofrequency links and compares well with recently demonstrated full optical links.Comment: 11 pages, 5 figure

Примерная тематика дипломных работ

In this paper,a comparative study of various transistors dedicated to low phase noise S to X bands oscillator design is proposed.Then,a transistor selection factor for low phase noise oscillator design is introduced

Областная газета. 2006. № 282/283. Ветеран Среднего Урала

Abstract—The photodiode impact on the phase noise of an optical link, and particularly its ability to convert the laser amplitude noise into microwave phase noise, is studied and modeled. The model involves a nonlinear RC cell which describes a photogeneration delay which is a function of the optical power. The whole system is then implemented on a microwave CAD software, and the link gain and phase noise performance are computed. Keywords—photodiode; nonlinear modelling; CAD; microwave-optics; phase noise; optical fiber link I

Role of alkali ions in the radiation sensitivity of the quartz material

International audienc

OSCILLATEURS OPTOELECTRONIQUES TOPOLOGIES, PERFORMANCES ET PERSPECTIVES

National audienceUne synthèse des travaux sur les oscillateurs électro-optiques est présentée, en particulier ceux menés ces dernières années en France dans le cadre de différents consortiums de recherche. Les résultats obtenus sont comparés aux alternatives existantes en hyperfréquences

Reliability investigation in SiGe HBT’s

This paper addresses some reliability properties of SiGe HBTs. We first verified that no major problems were related to the SiGe layer through DC life tests. In the second step, we investigated the hot carrier influence on the DC, noise and microwave properties of these devices. We found that some degradation was occurring at the extrinsic base region in the vicinity of the emitter associated with some surface recombination. These assumptions have been described by physical simulations and confirmed by low frequency noise characterization. Finally, it has been demonstrated that microwave properties are affected by the mechanism and we propose a bias method that results in its minimization