Simultaneous dual-band frequency-agile microwave signal generation with a dual loop Fourier domain mode locked optoelectronic oscillator

We propose and demonstrate a dual-band Fourier domain mode-locked optoelectronic oscillator (FDML-OEO) for simultaneously generating two frequency-agile microwave signals by deploying two rapidly tunable and independently reconfigurable bandpass microwave filters (TBF) parallelly placed in two RF feedback loops. By adjusting the drive signals of two TBFs, dual-band linearly chirped microwave waveforms (LCMWs) can be generated. In particular, by driving the two TBFs with different waveforms, Costas-coded linear frequency modulation waveforms (LFMWs) with different coding patterns and different chirping rates at two different frequency bands are successfully generated in our experiments. In addition, the central frequencies of two frequency bands are independently tunable. Our approach has the potential to generate agile broadband multi-format radar waveforms with low phase noise and excellent pulse-to-pulse coherence directly from an OEO, which can be applied to advanced multi-band radar and wireless communication systems.