A 24.9~34.5 GHz Injection-Locked Frequency Tripler Based on Top Differential Injection of Resonator

This paper proposes a broadband injection locking scheme to solve the problem of narrow locking bandwidth of traditional injection-locked frequency Tripler (ILFT). The scheme utilizes the differential injection technology to improve the even-order harmonics rejection ratio and injection signal current. The top injection technology of resonant tank based on transformer coupling is adopted to avoid the loop gain deterioration with using traditional source nodes injection and extend the locking bandwidth. The circuit is designed in a 55-nm CMOS process. The simulation results show that a 24.9~ 34.5 GHz (32.3% bandwidth) locking range has been achieved with the condition of lv supply voltage and 5dBm injected power. The DC power consumption of the core circuit of ILFT is 5. 07mW. The first, second, and fourth harmonic rejection ratio in the lock center is greater than 40 dBc.