A 2.4-GHz CMOS VCO is presented employing pMOS transistors as voltage-controlled capacitances and on-chip hollow spiral inductors. The design was implemented in a standard digital 0.8 /spl mu/m CMOS process and exhibits a 15% tuning range at 2.5 V supply voltage and 9 mA supply current. Phase-noise measurements show a phase-noise of about -118 dBc/Hz at 1 MHz from the carrier.
['Pietro Andreani', 'Sven Mattisson']
A 2.4-GHz CMOS monolithic VCO based on an MOS varactor