Wide-Locking Range Divide-by-3 Injection-Locked Frequency Divider Using Sixth-Order $RLC$ Resonator

A wide-locking range divide-by-3 LC injection-locked frequency divider (ILFD) is proposed and implemented in the TSMC 0.18-μm 1P6M CMOS process. The divide-by-3 ILFD uses a cross-coupled nMOS pair, an injection MOSFET pair, and a sixth-order RLC resonator. The divide-by-3 ILFD has three oscillation frequency bands and three locking ranges. At the drain-source bias V
_DD
of 0.9 V and at the incident power of 0 dBm, by switching a varactor bias, the high-band, middle-band, and low-band locking ranges of the ILFD are, respectively, given by 3.47 GHz (33.87%) from 8.51 to 11.98 GHz, 3.72 GHz (54.86%) from 4.92 to 8.64 GHz, and 1.05 GHz (19.76%) from 4.88 to 5.93 GHz. The operation range is 7.1 GHz (84.2%) from 4.88 to 11.98 GHz. The ILFD-core power consumption is 6.759 mW. A wider locking range of 4.43 GHz (67.07%) from 4.39 to 8.82 GHz is obtained by overlapping the three locking ranges at a fixed bias condition. The die area is 0.991 × 1.04 mm
²
.