High-efficiency X-band HBT power amplifier

We report on the state-of-the-art performance of monolithic HBT amplifiers at X-band. Single-chip, two-stage amplifiers have been designed and fabricated using AlGaAs/GaAs HBT process. An output power level of 12.5 W, with 51% power-added efficiency and 13 dB associated gain have been achieved at 8.5 GHz. The amplifier delivers more than 10 W output power with minimum 41% PAE in the 8.3-9.5 GHz band, and 9 W power with minimum 38% PAE in the 8.3-10.0 GHz band. The amplifier measures 4.5/spl times/4.5 mm/sup 2/ in size and is thermally ballasted for reliable operation. To our knowledge, these results represent state-of-the-art performance in terms of the combination of power, bandwidth, and efficiency for any monolithic solid-state amplifier technology.<>