Low-Power-Consumption Wide-Locking-Range Dual-Injection-Locked 1/2 Divider Through Simultaneous Optimization of VCO Loaded $Q$ and Current

A new 1/2 dual-injection-locked frequency divider (dual-ILFD) with wide locking range and low-power consumption is proposed, analyzed, and developed together with a divide-by-2 current-mode logic (CML) divider. The chip was fabricated using a 0.18-μm BiCMOS process. The 1/2 dual-ILFD enhances the locking range with low-power consumption through optimized load quality factor (QL) and output current amplitude (i_OSC) simultaneously. The relationship between i_OSC and QL, and hence the locking range, is explained analytically. The designed 1/2 dual-ILFD also works as a free-running oscillator between 3.592 and 4.102 GHz without injection signals. The 1/2 dual-ILFD achieves a locking range of 692 MHz between 7.512 and 8.204 GHz. The current consumption of the designed core 1/2 dual-ILFD is 2.93 mA with 1.5-V supply. The designed 1/2 dual-ILFD increases the locking range by 9.9 times over a single-injection counterpart. The new 1/2 dual-ILFD is especially attractive for microwave phase-locked loops and frequency synthesizers requiring low power and wide locking range.