A 2.4 GHz low-power low-phase-noise CMOS VCO using spiral inductors and junction varactors

A completely integrated 2.4 GHz low-power low-phase-noise voltage-controlled oscillator (VCO) was implemented in a standard 0.18 /spl mu/m single-poly, 6-metal mixed-signal CMOS process. It employs junction varactors as voltage-controlled capacitances along with on-chip spiral inductors to form the LC-tank. The VCO-core draws 1.8 mA of current from a 1.2 V supply. Simulated phase noise is shown as -101.9 dBc/Hz at a 100 kHz offset from the carrier frequency of 2.4 GHz, and -122.1 dBc/Hz at a 1MHz offset. Comparison shows that this design has better performance than previously published similar results. This circuit is in process of being fabricated through the MOSIS Educational Program.