CMOS circuit techniques for millimeter-wave voltage-controlled oscillator and injection-locked frequency divider

Fabricated in a standard 0.18-μm CMOS process, a voltage-controlled oscillator (VCO) and a injection-locked frequency divider (ILFD) operating in the vicinity of 50 GHz is presented in this paper. By employing a parallel combination of transmission lines for the LC-tank, the phase noise of the VCO can be effectively reduced while maintaining better frequency accuracy and tuning range. Measurement indicates a phase noise of -97 dBc/Hz at 1-MHz offset for the 54-GHz VCO. With the multiple injection technique, an enhanced locking range of the 50-GHz IFLD is demonstrated.