30/20 GHz multiple/shaped beam satellite antenna

Abstract

AbstractThis paper clarifies the design method and radiation characteristic of a satellite antenna (which covers Japanese territory by multiple beams) and a shaped beam simultaneously. This antenna is an offset paraboloidal reflector antenna fed by multiple horns. the main features are the realization of a multiple beam which covers 4‐divided Japanese territory and a shaped beam which is adapted to the form of Japanese territory by one reflector, and the addition of an RF sensor which enables high‐precision pointing direction control.First, a multiple beam antenna and a shaped beam antenna covering the same service area are discussed. It is shown that the optimum reflector parameters are different and a combined multiple/shaped beam antenna covering most of the service area with high gain can be constructed. Next, the RF sensor needed for antenna pointing direction detection is considered. It is shown that the RF sensor can be admitted into the horn cluster for some positions of a beacon station. Finally, from the measurement at the fabricated antenna it is ensured that the increase in primary radiator loss is small due to the multiple/shaped beam sharing and the antenna gain agrees well with designed value. It is clarified that the practical configuration of multiple/shaped beam antenna can actually be realized.