High-Speed Weak Target Detection Method for Vortex Electromagnetic Wave Radar based on Bimodal Cyclic Baseline

Vortex electromagnetic (EM) waves can provide more target information, which is orbital angular momentum (OAM), than traditional plane waves in the field of radar detection. By emitting multiple different modes of vortex EM waves to illuminate the same target, the azimuth information of the target can be obtained. The Linear Frequency Modulated (LFM) radar is often used in current OAM radar design. However, for the detection requirements of high-speed weak targets, long-term accumulation is necessary to capture the target. Due to the high-speed motion of the target, the movement of the target between different modes’ echo signal cannot be eliminated after accumulation, making it difficult to compensate and extract correct target azimuth information. Therefore, this paper proposes a vortex EM wave high-speed target detection technology based on bimodal cyclic baseline. By alternately emitting vortex EM waves with OAM mode difference of 1, the mode phase information is not blurred while achieving long-term accumulation, thereby achieving distance, velocity, and azimuth detection of high-speed weak targets. Simulation results compared with traditional phase comparison azimuth measurement method proved the superiority of our method. The work and results provide suggestions to the development of vortex EM wave high-speed weak target detection.