Improvement of the three-meter Ka-band inflatable reflectarray antenna

An inflatable Ka-band (32 GHz) three-meter reflectarray is being developed to achieve low mass and small launch-vehicle stowage volume for future deep-space spacecraft telecommunication antenna applications. The reflectarray's reflecting array surface, being a flat "natural" thin-membrane surface, is believed to have better reliability for long space missions than a curved thin membrane "nonnatural" parabolic surface. A technology demonstration model of the inflatable reflectarray was previously developed with excellent radiation pattern characteristics but poor aperture efficiency. This article presents the development of a second model that has significantly improved the efficiency from the previous 10% to 30%. This improvement was achieved primarily by a correct new element design. The previous inflatable mechanical structure, developed for ground demonstration purposes, has also been improved to approach being a space-flight design.