GaInP/GaAs HBT technology for high power and high efficiency amplifiers at X-band

We report on the fabrication and performance of GaInP/GaAs heterojunction bipolar transistors (HBTs) and their successfull insertion in high power amplifiers at X-band frequencies. Discrete power transistors with optimized emitter ballasting and deep proton isolation have been developed. A typical power transistor cell delivers 0.6 Watt cw output power and 60% PAE at 10 GHz. Different types of monolithic amplifiers have been realized and tested. The largest power MMIC with 128 single fingers (emitter area 128 x 2 mu x 30 mu m) shows up to 9 Watt output power with 42% PAE (45% peak PAE) at 10 GHz under critical long pulse conditons (100 mu s, 10% duty cycle). To our knowledge these results represent the best performance of any GaInP/GaAs HBT MMIC power amplifier considering efficiency, output power, operation frequency and pulse conditions.