PURPOSE: To obtain the device which has redundancy and operates even when the electric power capacity of the unbalanced power absorbing resistance of a power composing circuit is small by supplying DC power from mutually different power circuits to amplifiers which are connected to power composing circuits in common, and supplying DC power from each power circuits to plural amplifiers.

CONSTITUTION: High frequency power amplifiers 1∼9 and power composing circuits 11∼14 are the same as before, but power circuits 31∼33 and the high frequency power amplifier circuits 1∼9 are connected differently. High frequency power amplifiers connected to an initial-stage power composing circuit in common are supplied with DC power from mutually different power circuits respectively. The power circuits 31∼33 are connected as mentioned above, so if one power circuits troubles, there is an input power unbalance generated among the power composing circuits 11∼13 of the initial stage, but the input power is balanced at the power composing circuit 14 of the final stage and the unbalance is eliminated. Consequently, the power absorbing resistance of the final-stage power composing circuit which requires the largest power capacity may be small. Thus, the main device has redundancy because of the plural power circuits 31∼33.