Phase-Locked Tri-Band Broadband Signal Generation From Injection-Locked Fourier Domain Mode-Locked Optoelectronic Oscillator

We propose and experimentally demonstrate a scheme for generating phase-locked tri-band linearly frequency modulated (LFM) and frequency-shift-keyed (FSK) microwave waveforms using an injection-locked Fourier-domain mode-locked optoelectronic oscillator (FDML OEO). The system consists of optical link and electrical links, where coherent broadband signals from the three electrical branches are mutually locked within the loop by injecting a single-tone signal from signal source, being followed by the implementation of synchronous signal outputs with maximum frequency-sweeping bandwidth (FSBW) of 400 MHz through tunable bandpass filter (TBF). The FSBWs and central frequencies of different types of waveform signals generated by FDML OEO can be adjusted freely by the TBF. The experimental results show that the output signals across the three bands demonstrate good tunability, synchronization and high coherence. These advantages present great potential for future applications in microwave and radar systems.