On-off intermittency observed in a mutually coupled phase-locked loop system

On-off intermittency is observed in a mutually coupled phase-locked loop (PLL) system for both experiments and simulations. The system has two couplers between two PLLs for coupling and is designed to give good correspondence with dynamic systems with a periodic potential. In simulations, numerical calculations are performed on the governing equations of the PLL. In experiments, PLL IC modules and op-amps are used as PLL-cores and key components of couplers, respectively. The simulation results show coincidence with those of experiments. The properties of the burst signal in the observed intermittent signal are: the -1 power law of the amplitude distribution; and the -1.5 power law of the laminar duration time distribution. The power laws agree with the proper statistical features of the on-off intermittency