First Demonstration of AC Gain From a Single-walled Carbon Nanotube Common-Source Amplifier

Abstract

First demonstration of AC gain from a single-walled carbon nanotube transistor is presented. A top-gated carbon nanotube field-effect transistor (CNFET) is configured as a common-source amplifier and frequency response function of the amplifier is measured. Evidence of unambiguous signal amplification is observed in time domain as well as frequency domain up to a unity gain frequency of approximately 560 kHz. The observed roll-off in frequency is solely due to the RC time constant of the measurement apparatus. A specifically designed circuit compatible SPICE model for the CNFET is used to model both DC and AC characteristic with the same set of physical parameters for the first time. Good agreement between measurement and simulation is obtained. For a device without the parasitic load capacitance, the predicted intrinsic unity voltage gain frequency is 29 GHz and the cut-off frequency is ~ 50 GHz.