Advances in the design of solid-state power amplifiers for satellite communications

The development of solid state power amplifiers (SSPAs) began in the mid-1970s, on the basis of the emerging GaAs FET device technology. Attention is presently given to the SSPA replacement of travelling wave tube amplifiers in satellite communications systems, which now number over 100 in geosynchronous satellites. The operation of these transponders to date has demonstrated significant improvements in channel capacity, primarily in virtue of the linearity of which SSPA operation is capable. Design features and test results for several advanced SSPAs that are intended to operate at higher output powers than earlier devices are presented.