Ultra-Wideband Reconfigurable Radar Waveform Generation Based on Optical Recirculating Frequency Shifter Loop

We propose and experimentally demonstrate an approach for generating ultra-wideband reconfigurable radar waveforms using a recirculating frequency shifter (RFS) loop. In the proposed system, a RFS loop is used to achieve substantial bandwidth extension. Within this architecture, the frequency-modulated optical seed signal undergoes simultaneous temporal and spectral stitching, producing a wideband frequency-modulated optical output signal. By beating the output optical signal of the RFS loop with a continuous-wave optical signal, ultra-wideband reconfigurable radar waveforms can be generated. An experimental demonstration is performed, in which linearly-chirped and frequency-stepped microwave waveforms with a maximum bandwidth of 24 GHz are generated, showcasing the system's capability to produce diverse waveform types with substantial bandwidth. This versatile technique presents new possibilities for adaptive radar systems requiring high-performance waveform agility across multiple operational scenarios.