Weak RF Signal Detection Based on Single-Mode Optoelectronic Oscillator

We propose a weak radio frequency (RF) signal detection scheme based on single-mode optoelectronic oscillator (OEO). In this scheme, the phenomenon of injection locking is avoided by using the structure of phase-locked loop (PLL), which guarantees that the OEO works under the quasi-locked condition. The structure of PLL also stabilizes the gain provided to the RF signal under detection. Consequently, the maximum gain provided to the RF signal under detection is 59.49 dB and the detection sensitivity is −120 dBm.