Microwave Multiple-State Resonant Tunneling Bipolar Transistors.

Fabrication and microwave performance of a multiple-state resonant- tunneling bipolar transistor (RTBT) are presented. This novel transistor exhibits a maximum dc current gain of 60 at room temperature and a cut-off frequency of 24 GHz. Frequency multiplication by a factor of 5 has been demonstrated with a single transistor as opposed to conventional multipliers which use a phase-lock loop and a digital frequency divider.