Low phase noise current starved ring VCO on MOS capacitance

Abstract

In Wireless communication system VCO is major part which regulates the frequency according to the voltage. Ring oscillator of one type of VCO is used. The topology of Ring oscillator is current starved Ring VCO, is used. In this topology the oscillation frequency is regulated by MOS capacitance. MOS capacitance is added at the end of every stage of inverter.180 nm CMOS technology is used in this paper. The supply voltage is 1.8V and control voltage is varied from 0V to 1.8V. The simulated results are shown that good tuning range from 2.06GHz to 2.62 GHz. which is used in application of wireless system. The phase noise is measured-112dbc/Hz at 1MHz.