A 5-10 GHz, 1-Watt HBT amplifier with 58% peak power-added efficiency

Four 0.25-W GaAs Heterojunction Bipolar Transistors (HBT's) were combined in a single-stage hybrid microstrip amplifier. An output power of minimum 1 Watt (W) was achieved over the 5.5-9.5 GHz band with >48% power-added efficiency (PAE). The peak PAE was 58% at 7 and 9.5 GHz with an average efficiency of 52% over the 5-10 GHz band. This result was reproduced on two more units with a minimum efficiency of 48% and an average efficiency of 51%. To our knowledge, this is the highest efficiency obtained from any 1-W amplifier covering 5-10 GHz bandwidth.<>