A CNT based VCO with extremely low phase noise and wide frequency range for PLL application

Voltage controlled oscillators (VCOs) are used as key components in phase-locked loop systems for generating stable oscillation signals. Since the digital electronics industry increasingly needs a faster operation, VCOs need to generate signals at higher frequencies. This paper presents a voltage controlled oscillator with a wide frequency range and very low phase noise by using carbon nanotube technology. The Stanford CNTFET model is implemented in Verilog-A, and the proposed CNTFET VCO is simulated using ADS software. Simultaneous use of forward bulk biasing and an inductor yields a carbon nanotube oscillator with a frequency range of 6-20 GHz and a phase noise of -123 dBc/Hz.