A CNTFET Oscillator at 461 MHz

This letter presents design, implementation, and characterization of the first reported carbon nanotube field-effect transistor (CNTFET) RF oscillator. The circuit is implemented with discrete CNTFETs mounted on standard FR-4 substrate with off-the-shelf surface-mount-device components. The oscillator topology is similar to the phase shifter oscillator and uses two cascaded common source stages to provide enough gain for self-sustained and self-startup oscillation. The oscillator tank is merged with the matching network between two stages. The circuit oscillates at the frequency of 461 MHz with a phase noise of -115 dBc/Hz at 1 MHz and power consumption of 60 mW. While limited in output power by the driving capabilities of prototype CNTFETs, which still have a large density of residual metallic tubes, both power consumption and phase noise compare well with established and mature technologies. Moreover, the presented phase noise measurements provide a useful benchmark for the physical noise models being currently developed for this category of devices.