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

Abstract

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.