Interference-Resistant Photonically Generated Orthogonal Pair Multi-Chirp-LFM Waveform

We propose and demonstrate a photonically generated orthogonal up-down-chirp pair based multi-chirp linear frequency modulation (Ph-O-MLFM) radar waveform that offers inherent interference-resistant capability in detecting target objects in a multi-radar environment. As a proof-of-concept demonstration, in a simulation setup, we generate 4GHz, 1µs, Ph-O-MLFM and commonly used photonics-based LFM (Ph-LFM) signals using a dual-drive Mach-Zehnder modulator (DDMZM) incorporating photonics-based bandwidth synthesis. To evaluate the performance, we compare the effects of varying chirp rate and time period LFM interference signals on object detection with Ph-LFM and the proposed Ph-O-MLFM waveforms by analyzing the range profile obtained from the matched filtering method. The results demonstrate that the Ph-O-MLFM waveform mitigates LFM interferences with a peak-to-sidelobe power level of >11dB, and a range resolution of 4cm, whereas the Ph-LFM waveform is susceptible to coherent LFM interference. These results highlight the potential utilization of the proposed Ph-O-MLFM waveform in multi-radar environments.