An LC-VCO with one octave tuning range

This paper presents a fully integrated low power and low phase-noise VCO, having a tuning range over one octave (1.2 GHz to 2.5 GHz). The architecture is fully differential and the differential tuning offers a common-mode rejection of 31 dB. The VCO is implemented in a 0.18/spl mu/m CMOS process using a 1.8 V supply. The circuit, including the bias, consumes only 11.6 mW at 1.2 GHz oscillation frequency, the phase-noise is -129 dBc/Hz at 1 MHz frequency offset.