Microwave Vortex Imaging Based on Dual Coupled OAM Beams

This paper investigates electromagnetic (EM) vortex imaging based on dual coupled orbital angular momentum (OAM) beams. An OAM-generating scheme is proposed to generate radio waves carrying various dual coupled OAM at the X-frequency band and the experimental results of radar imaging in an anechoic chamber are illustrated for the first time. The uniform circular array (UCA) is exploited to generate dual coupled OAM beams and the radiated fields are presented by both theoretical analysis and full-wave EM simulation. Subsequently, the mathematical imaging model is established and the target reconstruction method is proposed. The relative imaging error (RIE) is introduce to evaluate the imaging performance. The imaging results indicate that the proposed method can have a better performance than EM vortex imaging without OAM-multiplexing and save half time of OAM beams transmitting. Moreover, the imaging experimental results in the anechoic chamber validate the effectiveness of the proposed method. This paper applies OAM-multiplexing beams to radar imaging and improves the vortex imaging efficiency, which can benefit the applications of OAM beams and the design of OAM-based radar systems.