Bipolar Heterojunction Transistors: Out of Models into Reality

The modelled and measured capabilities of the Bipolar Heterojunction Transistor are reviewed. The device is shown to have potential in high speed digital ICs and in microwave power amplification. It has demonstrated a world beating record for high speed divider circuits but is being hotly pursued by the Silicon Bipolar Junction Transistor. On paper it has promised much and it is now becoming a reality.