A W-Band 2nd Subharmonic Injection-Locked Phase-Locked Loop with Large Locking Range

This paper introduces a simple approach to obtain the equivalent locking range of the 2^nd subharmonic injection-locked phase locked loop (S-ELPLL). Furthermore, the phase noise of the 2^nd S-ILPLL is analyzed by using a linear phase noise model. Finally, a W-band 2^nd S-ILPLL circuit was designed and tested; the experimental results demonstrate that the locking range is 60 times larger than that of the 2^nd subharmonic injection-locked oscillator (S- ILO) . On the other hand, the phase noise will not deteriorate in the entire locking range as compared with that of the S-ILO. Therefore, it can be used in novel millimeter wave frequency synthesizer.