Abstract
An LC divide-by-2/3 injection-locked frequency divider (ILFD) is described, where a pair of switched capacitors is used to select the division ratio between 2 and 3. The locking range analysis of the ILFD based on the gain and phase conditions is discussed. Based on the analysis, the optimized bias current in order to achieve the maximum locking range for the ILFD is obtained and is verified through measurement. The circuit was fabricated in a 0.18 mu m CMOS technology. The input frequency of the divide-by-2/3 ILFD is from 4.28 to 4.81 GHz with an input power of -0.5 dBm. The power consumption of the ILFD is 3.15 mW at 1.8 V supply voltage. (C) 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:337-340, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25694