Heterojunction bipolar transistor technology for defense and commercial applications

GaAs heterojunction bipolar transistors (HBTs) have undergone a transition from defense applications to low cost, high volume commercial products for the portable wireless market. In particular, GaAs HBTs have traditionally targetted the front-end interface for RF transceivers, but their insertion has broadened to encompass demodulation, frequency conversion, digitization and clock-recovery functions. As GaAs HBTs establish their presence in the commercial arena, new device technologies are emerging offering better performance and innovative system and circuit options.