A 2.4-GHz sub-mW frequency source with current-reused frequency multiplier

A fully integrated 2.4 GHz low-power frequency source including a 1.2 GHz voltage-controlled oscillator (VCO) and a current-reused frequency multiplier is fabricated in 0.18-/spl mu/m CMOS process. The proposed frequency source tunes from 2.22 GHz to 2.45 GHz by changing control bias from 0 V to 0.7V, and achieves a phase noise of -115.83 dBc/Hz at 1 MHz offset from a 2.2 GHz carrier frequency while drawing only 840 /spl mu/A bias current (490 /spl mu/A for a 1.2 GHz VCO and 350 /spl mu/A for the frequency multiplier) from the low supply voltage of 0.7 V.