Phase regeneration effect in mutual synchronization of oscillators

Many reports have been published on the mutual synchronization of several oscillators. Most of them, however, deal with the case of oscillators of the same frequency, and no reports are known for the case when an external signal is supplied to synchronizing oscillators having different frequencies. This paper discusses the mutual synchronization and stability of two oscillators with frequency ratio of 1:2. Synchronization is discussed when a signal of almost the same frequency as the lower of the two oscillators is injected together with the phase response of the oscillator when a PM signal is injected. It is shown that mutually synchronizing oscillators exhibit a phase regeneration effect. Furthermore, it is shown experimentally that there is a phase regeneration effect and an accompanying noise suppression.