Carbon Nanotube Technology for RF Amplification

ABSTRACT: Carbon nanotubes (CNTs) have great potential for high performance RF applications. Theoretical study has shown that the electrical current in a CFET is intrinsically linear. Today, linearity is the underlying limitation in increasing the data transport densities of wireless networks. The complex modulation protocols used to achieve higher data rates requires linear amplifiers. Increasing linearity in current bulk semiconductors is done by driving higher currents through large transistor channels and limiting the RF operating region to the most linear portion of the depletion curve. This wastes power and generates heat. The intrinsic linearity of CNTs offers significant improvements in spectral efficiency without sacrificing power. Modeling of past results reveals that the key limitations to achieving superior linearity in CFET devices are contact resistances and Schottky barriers formed at the interfaces between CNTs and their contacting materials. In addition, material purity plays a role in CFET performance. This project addresses the contact resistance issue and the need for high purity channels by combining novel fabrication techniques, and materials. The results of this study are important for guiding subsequent process improvements and for uncovering remaining technological barriers to a manufacturable CFET process technology. ; BENEFIT: High Linearity Amplifiers, mixers and RF components for use in high performance wireless transceivers. These components will enable higher data rates and increased spectral efficiency while consuming significantly less power. High performance RF amplifiers are important for commercial, scientific, and military applications alike.