Large spacecraft antennas: Conical ring-membrane reflectors

A 1.83-m diameter furlable conical Gregorian antenna based on a novel spoke-supported ring-membrane concept has been successfully demonstrated. Mechanical measurements of the conical reflecting surface, as well as BE gain measurements at Ku-band, show an rms surface deviation from the proper conical surface of 0.3 mm and a repeatability after multiple furling-unfurling cycles of + or - 0.05 mm. Design features and performance characteristics of this antenna indicate that the spoke-supported ring-membrane concept is a promising approach for producing large, furlable, lightweight, conical reflectors for spacecraft high-gain antennas.