Low-power quadrature voltage-controlled oscillator formed with two injection-locked frequency dividers

This article presents a new low-voltage n-core quadrature voltage-controlled oscillator (QVCO), which consists of two low-voltage n-core cross-coupled voltage-controlled oscillators (VCOs) with two injection MOSFETs in shunt with inductors used for inductive voltage boosting, and the QVCO coupling mechanism is the injection locking.The proposed CMOS QVCO has been implemented with the TSMC 0.18 μm CMOS technology, and the die area is 0.86 × 0.75 mm2. At the supply voltage of 0.7 V, the total power consumption is 0.847 mW. The free-running frequency of the QVCO is tunable from 4.44 to 5.25 GHz, as the tuning voltage is varied from 0.0 to 0.7 V. The measured phase noise at 1 MHz frequency offset is −118.21 dBc/Hz at the oscillation frequency of 4.615 GHz, and the figure of merit of the proposed QVCO is −192.91 dBc/Hz. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1170–1173, 2012