A 2.4GHz low power low phase noise ring VCO

This paper presents a low power low phase noise ring voltage controlled oscillator(VCO). The VCO consists of two stage differential delay cells which use transmission gates control delay. By using cross-coupled PMOS pair and compensation resistors in each delay cell, performance of the VCO is further improved. This VCO has been designed using 90nm CMOS technology with 1.2V power supply. Simulation results show that the VCO can operate from 1.1GHz to 3.2GHz, by varying the control voltage from 0.5v to 1.2v, the phase noise at 1 MHz offset from 2.4 GHz is -94 dBc/Hz. Its power consumption at 2.4GHz is 0.9mW, area of VCO is 12μm by 13μm.