An ultra low power 2.4GHz CMOS VCO

Abstract

A low power voltage-controlled oscillator (VCO) for IEEE 802.11b direct conversion receiver is demonstrated. The VCO is fabricated by TSMC 0.25-mum; based on the measurement results, the tuning range is 187MHz (7.78%); phase noise is -73.62dBc/Hz@600kHz offset and -82.44dBc/Hz@1MHz offset at 2.4GHz. The circuit draws only 53 muA current for the VCO core from a 1.5V supply.