A fully monolithic broadband power amplifier for Ku-band communications satellite applications

An attempt was made to demonstrate a fully monolithic SSPA module for application to Ku-band direct-radiating array antennas. The module design approach incorporates the necessary tradeoffs to simultaneously achieve good performance in efficiency and linearity, in addition to meeting the necessary gain and output power requirements over the full 10.7- to 12.75-GHz band. The authors describe a three-stage monolithic microwave integrated circuit (MMIC) amplifier being developed for this application with a peak efficiency of 33% at a C/I3 of 16 dB, and a nominal gain of 20 dB. To achieve this performance, the FET structure was optimized for efficiency, using broadband harmonic terminations, and the first two stages were designed to operate at sufficient backoff to minimize their contribution to overall nonlinearity. The results show the validity of the basic SSPA design approach and prove that a high-performance amplifier suitable for satellite communications applications can be achieved in fully monolithic form