Furlable spacecraft antenna development

Recent activities at JPL directed toward the development of large furlable spacecraft antennas using conical main reflectors are described. Development of two basic antenna configurations conceived at JPL and utilizing conical main reflectors was pursued. A 4.3-m (14-ft)-diameter model based on the two-reflection conical-Gregorian concept and a 1.8-m (6-ft)-diameter model based on the four-reflection Quadreflex concept have been made and RF-tested. RF gain measurements for the 4.3-m (14-ft)-diameter conical-Gregorian model were 48.83 db at X-band (8.448 GHz) and 37.82 db at S-band (2.297 GHz). These gains correspond to efficiencies of 53.6 and 57.5%, respectively. RF gain measurements for the 1.8-m (6-ft)-diameter Quadreflex model were 47.59 db at Ku-band (16.33 GHz) and 41.30 db at X-band (8.448 GHz), corresponding to efficiencies of 58.6 and 51.5%, respectively.