27 research outputs found
Computer-aided design and GaAs realizations of 4.8 and 9.6 Gbit/s optical receivers
Up until now the simplified "real frequency" technique has been applied to the design of broadband multistage microwave amplifiers where gain and VSWR are optimized, In this paper we extend the method to the design of transimpedance amplifier for a wide band optical receiver . So the noise is optimized in parallel with the gain and VSWR. The synthesis of the networks (equalizer) is carried out in two ways, with lumped elements arid distributed elements. Then we give several examples of design ; transimpedance amplifier and ultra wide band GaAs amplifier
C.A.D for broad-band multistage microwave transimpedance amplifier.
In high data rate optical-fiber, it is necessary to employ an ultra broad-band transimpedance amplifier. In this paper, we present a technique for the design of a transimpedance amplifiers. It can be applied as well to the design of interstage equalizers for microwave transimpedance amplifiers. In the version described in this paper, the optimisation process is applied to the transimpedance gain and noise which is adjusted. Based on the load charge matching technique, a sequential procedure to design multistage microwave transimpedance amplifiers is developed. The synthesis of network is carried out with lumped elements. Then we give an example of design of a two stage 3-7 GHz transimpedance amplifier with HEMT transistor
Le logiciel FREEL : réalisations en technologie hybride et monolithique d'amplificateurs microondes large bande pour dispositif de réception numérique sur fibre optique à 4,8 Gbit/s
In fiber optic very high datarate systems it is necessary to have an ultra large band high gain low noise amplifier after the front-end. The purpose of this paper is to show how powerful analytical techniques, such as the real frequency technique, may be applied to the design of a 6 MHz-6 GHz amplifier. According to the theory a two stage monolithique amplifier gives 17 dB gain and a 3 stage hybrid amplifier 16 dB across the band.Dans les systèmes à haut débit sur fibre optique il est nécessaire de disposer en réception d'un amplificateur ultra large bande à haut gain et bas niveau de bruit. Ce papier a pour but de montrer comment une technique analytique puissante, comme la méthode des fréquences réelles, peut être appliquée à la conception d'un amplificateur 6 MHz-6 GHz. En accord avec cette théorie deux réalisations ont été faites, une en monolithique (amplificateur à deux étages avec 17 dB de gain) et une en hybride (amplificateur à trois étages et 16 dB de gain)
Optimisation et synthèse d'amplificateurs micro-ondes par la méthode des fréquences réelles
In many applications such as in communication or surveillance systems we require broadband microwave amplifiers. The purpose of this paper is to give simple and efficient broadband matching techniques for microwave transistors. The computer-aided design procedure utilizes only the measured scattering parameter of the FET devices (« real frequency » technique). The optimization process is carried simultaneously on the transducer power gain and the VSWR. Applications of the technique are given on a 8-12 GHz amplifier and a 19-21 GHz amplifier.La méthode des « fréquences réelles » introduite par Carlin [1, 2] est basée uniquement sur la connaissance des paramètres de répartition S ij des transistors ; son utilisation ne nécessite aucun modèle de TEC. Le programme de CAO présenté utilise la procédure de Carlin. L'efficacité de la méthode, après modifications [3], permet aussi de concevoir des amplificateurs à plusieurs étages optimisés simultanément en gain et en TOS. Cette méthode tient compte de la non-unilatéralité des transistors
Network synthesis applied to the design of tuned optical front-ends for microwave lightwave systems
Genetic Characterization of Newly Reintroduced Dengue Virus Type 3 in Martinique (French West Indies)
Dengue type 3 viruses were isolated from patients in Martinique between 1999 and 2002. This serotype had not been detected on the island in the last 20 years. Genomic sequence determination and analysis showed great stability of the virus during the period studied
Clinical research in radiation oncology: how to move from the laboratory to the patient?
International audienceTranslational research in radiation oncology is undergoing intense development. An increasingly rapid transfer is taking place from the laboratory to the patients, both in the selection of patients who can benefit from radiotherapy and in the development of innovative irradiation strategies or the development of combinations with drugs. Accelerating the passage of discoveries from the laboratory to the clinic represents the ideal of any translational research program but requires taking into account the multiple obstacles that can slow this progress. The ambition of the RadioTransNet network, a project to structure preclinical research in radiation oncology in France, is precisely to promote scientific and clinical interactions at the interface of radiotherapy and radiobiology, in its preclinical positioning, in order to identify priorities for strategic research dedicated to innovation in radiotherapy. The multidisciplinary radiotherapy teams with experts in biology, medicine, medical physics, mathematics and engineering sciences are able to meet these new challenges which will allow these advances to be made available to patients as quickly as possible