A highly-linear highly efficient HBT for communications circuits

A Martin Marietta Laboratory heterojunction bipolar transistor, which was fabricated using a base-emitter realigned process to reduce surface recombination, has been load pulled to demonstrate that it is simultaneously highly linear and efficient. Achieving a breakthrough in highly linear C-band communications power amplification, the HBT demonstrated a linearity of 30 dB C/I, typically required by communications systems, with 61% power added efficiency at 6 GHz. When tuned for maximum efficiency it achieved 72% P.A.E.