LC-tank injection-locked frequency divider (ILFD) is a high-speed and low-power FD, the use of inductor in ILFD increases the voltage swing in the circuit and the ILFD is subjected to stressing damage. This book reports the RF performance of CMOS LC ILFDs under over-voltage operation to accelerate the study. Although it is well-known an ILFD will have degradation in RF performance after hot-carrier stress. It is not clear how the degradation shows up in the ILFD characteristics. The experimental studies bridge the gap between the real degradation phenomena and a concept that an ILFD has degradation after hot-carrier stress. The studied circuits include even-modulus and odd-modulus ILFDs.