A 21-GHz-band Advanced Satellite Broadcasting System

A previously proposed variable equivalent isotropic radiated power (e.i.r.p.) satellite system, which uses phased array antenna technology to increase the radiated power only in areas of heavy rainfall, has now been conceptually applied to the future 21-GHz-band broadcasting satellite system. Using various parameter values for the antenna, we evaluated the radiation patterns that result when forming a nationwide beam in the shape of the Japanese landmass, for various antenna aperture diameters and numbers of spot beams. We confirmed the feasibility of our proposed phased array system by computer simulation. We then calculated the values of the major parameters, such as the antenna weight required for estimating the satellite bus. We also clarified the satellite scale in terms of required mass at launch and subsequently proposed different scales. As a result, we demonstrated that a 21- GHz-band broadcasting satellite system can be realized with a phased array antenna in terms of satellite buses and rocket systems.