Frequency multipliers using InP-based resonant-tunneling high electron mobility transistors

Frequency multipliers (doubler and tripler) are demonstrated at room temperature, using a simple circuit that combines a load resistor with an InP-based resonant-tunneling high electron mobility transistor (RTHEMT). The RTHEMT incorporates an InGaAs/AlAs/InAs pseudomorphic resonant tunneling diode into the source of a nonalloyed ohmic contact InAlAs/InGaAs high electron mobility transistor. A nearly flat valley current is obtained in the RTHEMT's current-voltage characteristics, which results in pronounced negative transconductance throughout a wide range of drain-to-source bias voltages. As a result, frequency multipliers using RTHEMT's feature large output voltage swing and reduced power consumption.