A 1.8-GHz monolithic CMOS VCO tuned by an inductive varactor

In English A 1.8-GHz CMOS VCO is presented, employing a monolithic transformer as an inductance with voltage-controlled value. The design was implemented in a standard digital 0.6 μm, 2-metal CMOS process and exhibits a 10% tuning range with a 2.7 V supply voltage and a 9 mA supply current. Phase noise measurements show a worst-case phase noise of about -112 dBc/Hz at 3 MHz offset from the carrier