Power GaInP/GaAs HBT MMICs

GaInP/GaAs HBT technology is an excellent alternative to GaAlAs/GaAs HBTs. We present new X-Band power results both on discrete devices and on MMICs obtained using this new type of HBT. 12-2×30-¿m2 finger discrete devices show an output power of 1W at 10 GHz with a power added efficiency of 43% under near class A bias conditions. The dependence of the power gain on the HBT topology has been simulated and that predicts precisely the device performances. First power amplifier MMICs have been produced by Thomson-CSF. Those MMIC amplifiers achieve an output power above 1 W at 10 GHz under both CW and pulsed conditions. The power gain is higher than 12dB at 10 GHz. At the same RF frequency, the power added efficiency reaches 35% and 25% under pulsed conditions (3 ¿s, 10% duty cycle) and CW respectively. These first results are promising, and improved results are expected soon by tuning the output matching network and using higher gain devices.