5GHz Shunted PCNTFET-based hybrid-circuit VCO

A high-frequency and low-power Voltage-Controlled Oscillator (VCO) circuit has been proposed here. Thepresented structure is based on the three-stage Current-Starved topologies having compensated pull-up structure. Thecircuit is implemented using 32 nm technology of p-type and n-type Carbon Nanotube Field-Effect Transistors. The pcarriercompensation shunt structure is exploited for the second stage of the VCO to increase the rise time of theSchmitt trigger part. The presented shunted transistor topology demonstrates simultaneous improvement in thedissipation power and the oscillation frequency. On average, a 20% reduction in the power consumption, two timesenhancement in the oscillation frequency and larger tuning range are reported here with respect to previously presentedVCO topology. In addition, several design and characteristics parameters such as Gate oxide thickness, inter-CNT pitchand chirality are considered here and their impact on the power dissipation and the oscillation frequency is studied.

Keywords:

Current-Starved Voltage Controlled Oscillators , Carbon Nanotube FET , Schmitt trigger