La modélisation électromagnétique d'antennes spatiales

Les antennes embarquées sur les satellites sont soumises à de très fortes contraintes de développement. Etant un système critique d'un satellite, elles doivent répondre à des spécifications sévères tout en étant compatibles de l'installation sur une plateforme soumise à l'environnement spatial. La modélisation numérique est largement utilisée pour la conception de ces antennes. Toutefois, certains problèmes nécessitent d'améliorer les modèles numériques actuels pour répondre aux besoins des futurs systèmes spatiaux

Sub-reflectarray performances for reconfigurable coverages

International audienceA reconfigurable sub-reflectarray (RSRA) is studied to perform a realistic telecommunication scenario in Ku-band. The reflectarray panel is based on a proven technology with PIN diodes developed by Thales Airborne Systems and French Space Agency. This article presents different geometries of dual-reflector that can be used with this RSRA and the performances are compared, including quantization effects. It also presents that the main difficulty to tackle with RSRA is the alteration of the radiation patterns due to the specular radiation of the panel. Finally, two solutions to minimize this effect with RSRA are presented

Potentialities of reflector antennas with reflectarray feeds for reconfigurable coverage

International audienceConclusion The different results obtained with this antenna concept show some interesting potentialities. Indeed, directivities above 34 dB can be obtained on different shaped coverages without too much complexity for the reflectarray design and with an interesting compactness gain compared to classical dual reflector antennas. Moreover, the number of cells can be limited to a value below 2000 thanks to the reflector whereas more elements would have been necessary with a single reflectarray. This reduction is an important fact for the active cells consumption and manufacture. Another interest of this solution is the versatility of the active reflectarray panel. Once the optimized phase shifts have been synthesized, the panel has just to be electronically driven. A combination of several elementary panels can also be foreseen for versatility and manufacture easiness, which is contributing to a cost reduction. Other works on this concept are currently led to improve the performances and to afford flexibility on more than two coverages with a reduced cell numbers

1-bit and 2-bit transmit-arrays for X-band

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Design and demonstration of an X-band transmit-array

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X-band transmit-arrays with linear and circular polarization

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