MOS Capacitance Based 3-Stage Current Starved Ring VCO for Wireless Applications

This paper exhibits performance analysis of MOS capacitance based current starved ring voltage-controlled oscillator (VCO) comprising of three stages. In the designed VCO, the frequency is varied by varying the MOS transistor capacitance by applying a variable tuning voltage. Current source is used applying the technique of PMOS current mirror so the VCO is current starved. 3 stage current starved ring VCO based on MOS capacitance is designed and implemented in 90nm CMOS process technology. Simulations have been done with a supply voltage of 1 V whilst the controlling voltage differs from 0 to 0.6 V. Simulated performances show that the MOS capacitance based current starved design results in a better tuning range of about 4.22 to 6.22 GHz with a very low power consumption of about 0.368 mW. The figure-of-merit is −155.3 dBc/Hz with a phase noise of -77.87dbc/Hz at 1 MHz offset. The designed VCO can be used in wireless applications such as IEEE 802.11a.