Abstract Based on the understanding of the fundamentals of PLL, several different opinions about some problems in the paper-"A Quantitative Research of Nonlinear Behaviour of a Second-Order Phase-Locked Loop by Perturbation Method" are presented.
Li Mingzhong. A DISCUSSION ON“A QUANTITATIVE RESEARCH OF NONLINEAR BEHAVIOUR OF A SECOND-ORDER PHASELOCKED LOOP BY PERTURBATION METHOD”[J]. , 1985, 7(3): 195-202 .