SATELLITE BROADCAST SYSTEM

PURPOSE:To assign transmission power preponderantly to important area whose propagation loss is increased and to improve the line operation rate by connecting a transmission power amplifier to the radiators via variable power distributers and controlling the power distribution ratio of the variable power distributers so as to control the power for each element beam. CONSTITUTION:A monitor control CPU 34 extracts rainfall attenuation information of each area sent from a ground control station by using a signal from a frequency converter 24 and controls the distribution ratio of variable power distributers 261-267 based on the information and controls variable phase shifters 271-278 to make the relative phase difference between feeder paths zero thereby supplying the power of the same phase to each element beam. Thus, it is possible to assign transmission power preponderantly to an area whose propagation loss is increased due to rainfall or the like in the service area.