A mm-Wave CMOS LC-VCO With Vertically-Coiled Solenoid Inductor

This letter presents a small area mm-wave CMOS LC-VCO with vertically-coiled solenoid inductor. Based on the multi-layers of metals and the vias among them in CMOS process, vertically-coiled solenoid inductor with small area is formed with the inductance at the order of hundred pHs. An accurate compact model for the vertically-coiled solenoid inductor over a broad frequency range has been developed, the method to analytically extract the model parameters is also presented in details. A 24 GHz LC-VCO with the vertically-coiled solenoid inductor was implemented in 90 nm CMOS process. It occupies a core area of 250 μm × 85 μm, the measured phase noise is -122 dBc/Hz@ 10 MHz when the output frequency is 23.6 GHz.