Efficiency and power output of the quantum-well injection transit-time device

We report a theoretical analysis of the efficiency and power capability of the newly proposed quantum-well injection transit-time (QWITT) device. When compared with traditional semiconductor sources such as TED or IMPATT, our results show that the QWITT is a far better source at millimeter (mm) frequencies. The improved performance of the QWITT is due to the high intrinsic frequency response time, as well as to the extremely localized carrier injection mechanism and the utilization of the high transient velocity of carriers at small distances. Computer simulations with special consideration of these effects clearly confirm these merits. For example, at 300 GHz, a single QWITT can provide an output power of 1.2 mW at 7.4-percent efficiency when it is matched to a resonant circuit with about 1-Ω resistance.