Abstract
Behavior of two mutually coupled phase-locked or free-running oscillators with n earby frequencies is studied. In the case of two free-running mutu ally coupled oscillators, the two oscillators are either locked to a common frequency, or they undergo through a mutual pulling interaction. It is shown that center frequencies of the pulled oscillators come closer, however, they do not necessarily approach t oward each other from opposite directions. It is also demonstrated that the strengths of mutual injections as well as the phase-s hifts experienced by the mutually injected signals, affect location s of the two center frequencies. The paper also studies impacts of phase-locked loops on the location and magnitude of the sidebands, when the two mutually coupled oscillators are phase-locked. Effects of the phase-shifts endured by the mutually injected signals on the sidebands are also discussed.