A 16-GHz-band low-power and low-phase-noise PMOS VCO IC is presented in 40-nm SOI CMOS. The VCO IC includes a cross-coupled PMOS pair, an LC bias circuit, drain resistors, an LC tank circuit and novel feedback circuit. The feedback circuit which consists of a PMOS transistor, a resistor and a capacitor realizes robust start-up and low-power Class-C operation in the steady-state. The VCO IC is designed, fabricated and fully evaluated on wafer. The VCO IC has exhibited a measured phase noise of 㸫131.0 dBc/Hz at 10-MHz offset frequency from the 16.05 GHz carrier frequency with a supply voltage of only 0.43 V. The measured FOM is 㸫191.2 dBc/Hz.