Wide-Locking Range Dual-Band Injection-Locked Frequency Divider

A wide locking range divide-by-2 CMOS LC-tank injection locked frequency divider is proposed and is realized with two mixers in series and a cross-coupled oscillator with dual-resonance LC resonator to provide large output voltage swings at high-and low-frequency bands. The dual-band function can be obtained without switching. Measurement results show that at the supply voltage of 0.8 V, the free-running frequency is from 3.571 to 3.974 GHz for the high-frequency band and from 2.278 to 2.349 GHz for the low-frequency band. At V-tune = 1.2 V, an external injected signal power of 0 dBm provides a low-band divide-by-2 locking range (57.7%) from 2.87 to 5.2 GHz and a high-band locking range (25.7%) from 7.1 to 9.2 GHz. At V-tune = 0 V an external injected signal power of 0 dBm provides a high-band locking range (46.5%) from 5.6 to 9 GHz and a low-band locking range (25.0%) from 2.8 to 3.6 GHz. (C) 2013 Wiley Periodicals, Inc.