Novel current-voltage characteristics of an InP-based resonant-tunneling high electron mobility transistor and their circuit applications

We report novel current-voltage characteristics in an InP-based resonant-tunneling high electron mobility transistor (RTHEMT). The RTHEMT incorporates a resonant-tunneling diode structure into the source region of a HEMT. A near-flat valley current is obtained in the current-voltage characteristics. This unique feature leads to the observation of negative transconductance throughout a wide range of source-drain bias. Using a simple circuit that combines an RTHEMT with a resistor load, we demonstrate frequency multipliers (both doubler and tripler) and a three-valued logic inverse literal gate.