Microwave FSK Signal Generation Based on Optoelectronic Oscillator and PolM

We report a novel photonic approach for generating FSK microwave signal based on an optoelectronic oscillator (OEO) loop and a polarization modulator (PolM). A polarization-division multiplexing Mach-Zehnder modulator (PDM-MZM) is used in the OEO loop to obtain two microwave signals with two frequencies at two orthogonal polarization states. The optical signals modulated by two generated microwave signals of OEO are injected into a PolM with a proper adjustment of input polarization states. Applying a binary coding signal in the PolM, a FSK microwave signal can be successfully realized after photodetection. This proposed scheme is theoretically analyzed and experimentally proved. Experimental results demonstrate the generation of a 2Gb/s FSK microwave signal at 10/16 GHz. This work with no need of external microwave sources and low phase noise is pretty promising in integrated microwave systems for wireless communication and radar system.