Sub-nanosecond pulse characteristics of InGaP/GaAs HBTs

Using a novel sub-nanosecond pulse current-voltage measurement technique, InGaP/GaAs heterojunction bipolar transistors were shown to survive strong impact ionization and to have a much larger safe operating area than previously measured or predicted. As the result, an empirical model for impact ionization was constructed and added to a commercially available HBT model. The modified model can predict the HBT characteristics across the enlarged safe operating area, including strong avalanche breakdown and flyback. The modified model can be used to simulate not only the ruggedness of high-power amplifiers, but also the performance of ultra-wideband pulse generators.