Analytical analysis of phase-modulation-based frequency-tunable optoelectronic oscillators

Optoelectronic oscillators (OEOs) can realize ultra-low-noise radio frequency (RF) oscillations in the microwave or millimeter wave range. Most frequency-tunable OEOs (FTOEOs) use an electro-optic phase modulator, a narrow-band optical filter, and a frequency-tunable laser source to tune the RF oscillation frequency. This paper presents an analytical approach to signal and noise analysis of such FTOEOs, which is named here the phase transfer approach (PTA). The numerical conversion matrix approach (CMA) is also generalized to the analysis of FTOEOs. The PTA has the advantage of being simple and fast, whereas CMA has more abilities, such as considering the amplitude-to-phase conversion, but at the expense of more complicated implementation. The validity of PTA is verified by comparing its results with the CMA and other presented formulations in the literature.