Design of Low Phase Noise Cross-coupled VCO in 90nm CMOS Technology

A 2.5GHz low phase noise cross-coupled Voltage Controlled Oscillator (VCO) realized in 90nm CMOS technology is presented. High Q and low Q inductors are used in the design. The power consumption of the VCO is 25mW with the low Q inductor and 8.52mW with the high Q inductor. The tuning range for the two different designs is same, which is 13.2%. The phase noise of the two different designs are both below -120dBc/Hz at 1MHz offset frequency when the frequency of oscillation is 2.5GHz.