In an amplification section 1, in order to output RF signals outputted from amplification circuits 2, output connectors 3 are provided for the respective amplification circuits. The output connectors 3 are arrayed in the horizontal direction. A synthesis section 5 is provided with input connectors 6, to which RF signals outputted from the output connectors 3 of the amplification section 1 are inputted, so as to correspond to the respective output connectors 3. The input connectors are arrayed in the horizontal direction. The amplification section 1 and the synthesis section 5 are attachable/detachable by means of the output connectors 3 and the input connectors 6. A surface of the synthesis section 5 on which the input connectors are provided is set within the dimensions of a surface of the amplification section 1 on which the output connectors are provided.