This study presents the new locking range enhancement technique in divide-by-two injection locked frequency divider using a phase shifter circuit. The proposed divide-by-two phase shifter injection locking frequency divider (ILFD) is based on complementary metal–oxide–semiconductor (CMOS) cross-coupled oscillator with dual-resonance fourth-order LC-tank that is designed and simulated in 0.18 μmTSMC CMOS technology. Using a phase shifter branch, an extra current with a new phase angle towards oscillator current will inject into the LC tank and moves the locking angle to a new and wider angle that leads to a wide locking range. In an analysis, the effect of the phase shifter circuit on the proposed ILFD has been explained. Simulation results show that at a supply voltage of 0.95 V, the phase shift ILFD consumes 7.32 mW power and at the incident signal power of 0 dBm the locking range is 5.25 GHz, from 4.3 to 9.55 GHz and the relative locking range is 75.81%.
