A study on pattern synthesis method for array-fed reflector antenna for advanced direct broadcasting satellites

Satellite broadcasting services operated in the 12 GHz-band are currently provided in Japan. Furthermore, the technical development of areas such as future 21 GHz-band satellite broadcasting systems is also in progress. One of the major technical difficulties with the satellite broadcasting systems using such frequency bands is the large rain attenuation caused by heavy rainfall. A method for compensating for rain attenuation is necessary to avoid the interruption of broadcasting reception. We have been studying an advanced broadcasting satellite system having an on-board large-scale phased array antenna. This system can compensate for rain attenuation by increasing the radiation power over areas of heavy rainfall. The adaptive pattern synthesis technique of the phased array antenna makes it possible to reconfigure the radiation pattern (equivalent isotropically radiated power: EIRP) according to the distribution of rainfall on the service area. We describe the results of a basic study focused on (1) the radiation pattern requirements that systems such as broadcasting satellite systems with variable EIRIP will have to satisfy and, (2) pattern synthesis methods for an array-fed reflector antenna based on singular value decomposition (SVD).