Application of phased-array antenna technology to the 21 GHz broadcasting satellite for rain-attenuation compensation

The signal attenuation due to rain is greater in the 21 GHz band than in lower bands and this is one of the major factors limiting the availability of services in this band. A broadcasting satellite system is proposed in which phased-array antenna technology is applied to overcome the effect of rain-attenuation. Concentrated radiation beams created by a phased-array antenna cover areas of heavy rain, and the same antenna covers other areas with a spread radiation beam. We discuss the outline of this 21 GHz broadcasting satellite system and examine the major hardware elements, such as the array-fed reflector and a TWT suitable for an array configuration.