CMOS top-series coupling quadrature injection-locked frequency divider.

This article presents a new divide-by-2 injection-locked frequency divider (ILFD). The ILFD consists of a 2.1-GHz top-series quadrature voltage-controlled oscillator (QVCO) and two NMOS switches, which are in parallel with the QVCO resonators for signal injection. The proposed CMOS ILFD uses three-dimensional inductor to save chip area and has been implemented with the TSMC 0.18-μm CMOS technology and the core power consumption is 9.36 mW at the supply voltage of 0.9 V. The free-running frequency of the ILFD is tunable from 2.02 to 2.28 GHz. At the input power of -8 dBm, the total divide-by-2 locking range is from 3.6 to 6.05 GHz as the tuning voltage is varied from 0 to 0.9 V. The phase noise of the locked output spectrum is lower than that of free running ILFD in the ÷2 mode. The phase deviation of quadrature output is about 0.19°. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2554–2557, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23724 [ABSTRACT FROM AUTHOR]