High Output Port Isolation and Low Intermodulation Distortion Multi-Port-Amplifier

The multi-port-amplifier (MPA) is an innovative on-board power amplifier for multi-beam mobile satellite communications because it enables the efficient use of DC power and the flexible allocation of RF power. It is important for the multi-beam mobile satellite communications system using the MPA to reduce the signal interference in the adjacent beam overlap area and to reduce intermodulation distortion (IMD) caused by multi-carrier amplification. In an MPA, high output port isolation and low IMD are achieved by a novel combination of high power amplifier (HPA) arrangement and a demultiplexer/multiplexer configuration. This paper proposes an arrangement method of HPAs, which are the components of the MPA, to improve the isolation among the output ports without affecting the output power. An MPA configuration to reduce IMD is also proposed.