A Theoretical and Experimental Study of Injection Pulling in Phase-Locked Optoelectronic Oscillator under Radio Frequency Signal Injection

Starting with the single-loop optoelectronic oscillator (OEO), it is shown an analysis about the effects of a radio frequency (RF) injected signal on the phase-locked loop OEO. After obtaining the injection locking equation of the oscillator, it is derived the generalized locking equation and a time-domain model of a phase-locked loop OEO under RF signal injection is shown. Assuming the OEO is phase-locked to the reference signal and is injection-pulled by an independent RF signal, the behavior of the OEO is discussed. The frequency response of the spurious outputs due to RF injection signal in terms of the injection transfer function discussion is presented. An equivalent dual loop model of phase locked loop OEO under RF signal injection is presented for phase noise analysis. The presented analysis is partially supported by experimental results shown at the end.