Theory and small signal analysis for a new bipolar injection transit time device (BIPOLITT)

We have proposed and analyzed a new millimeter and submillimeter wave transit time device, the bipolar injection and transit time diode (BIPOLITT). The theory and small signal analysis for a two-terminal type rf operation is presented here. The device structure is similar to a heterojunction bipolar transistor (HBT) with an rf floating base. The relatively longer base is utilized to achieve an injection-phase delay close to 180/spl deg/. The collector depletion region is used as drift region. As an example, a BIPOLITT diode for 300-400 GHz operation is designed, and its small signal specific negative resistance is calculated to be about -3/spl times/10/sup -7/ /spl Omega//spl middot/cm/sup 2/.