MULTIPORT AMPLIFIER

PURPOSE:To arrange a reserve solid-state power amplifier(SSPA) for a fault of an SSPA without altering basic constitution for the improvement of the reliability of the multiport amplifier having plural input/output ports. CONSTITUTION:The number of SSPAs is made larger than that of a conventional multiport amplifier so as to reduce the influence of a fault of one SSPA, and several SSPAs 400 that minimize deterioration in isolation between output ports are selected and normally turned OFF as reserve SSPAs 500. The SSPAs are turned OFF at a certain rate to reduce sent electric power and power consumption. Consequently, a fault of an SSPA can be coped with without altering the basic constitution of the multiport amplifier, so the reliability can easily be improved. Further, the multiport amplifier can be placed in the best operation corresponding to communication traffic.