Active-inductor-capacitor tank colpitts injection-locked frequency divider

This article presents a wide-locking range injection-locked frequency divider (ILFD), using a tunable active inductor (TAI), which is used to extend the locking range and to reduce die area. The CMOS ILFD is based on a new Colpitts voltage-controlled oscillator (CVCO) with TAI-C tank and was fabricated in the 0.18-mu m IP6M CMOS technology. The ILFD is performed by adding injection MOSFETs between the differential outputs of the CVCO. At the supply voltage of 1.9 V, the free-running ILFD tuning range is from 2.25 GHz to 1.26 GHz, whereas the timing bias of active inductor is tuned from 0.88 V to 1.04 V. At the incident power of 0 dBm, the operation-locking range is from the incident frequency 1.25-5.85 GHz. The phase noise of the ILFD can track with the injection source. (C) 2008 Wiley Periodicals, Inc.