Performance capabilities of HBT devices and circuits for satellite communication

The heterojunction bipolar transistor (HBT) performance is studied, with emphasis on its possible utilization in satellite power amplifiers. After a review of the requirements of satellite power amplifiers, the suitability of HBTs is discussed in depth, including the output power capabilities, the realizable power-added efficiency and linearity, reliability considerations, and circuit aspects. Models and simulation tools for HBTs in power amplifiers are discussed, and the results obtained so far are given. A comparison of realized HBTs and various FET devices and circuits demonstrates that the HBT is a promising device for applications in satellite power amplifiers. The HBT will be a preferable device for microwave power amplification if the problems concerning the reliability can be solved, and further investigations will be performed to obtain larger devices with higher rated output power.<
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