Experimental evaluation of hot-carrier stressed series-tuned injection-locked frequency divider

This paper, for the first time, investigates hot carrier effect on a divide-by-2 injection-locked frequency divider (ILFD). The ILFD was implemented in the TSMC 0.18 μm 1P6M CMOS process. The ILFD uses direct injection MOSFETs for coupling external signal to the series-resonant resonator. It is shown that the locking range decreases and the oscillation frequency increases with stress time, and the phase noise in both the free-running and locked state increases with stress time. The measured operation range after RF stress also shows degradation from the fresh circuit condition.