Progress and prospect of microwave coincidence imaging(Invited)

Originated from the optical intensity ghost imaging, microwave coincidence imaging breaks through the limitation of antenna aperture on imaging resolution by space and time-varying radiation mode through the modulation of electromagnetic waves. It has the advantages of forward-looking, staring and fast-shooting imaging, and has broad application prospects in the fields of staring observation in key areas, autonomous sensing of unmanned systems, security inspection and security protection and so on. The technical origin of microwave coincidence imaging was briefly described, and its current research status and main progress from three aspects including the imaging principle, imaging methods and imaging systems were summarized. Through the analysis of the imaging principle, the basic conditions for coincidence imaging and the influencing factors of imaging resolution were clarified. Through the review of imaging methods, the differences and relationships among microwave coincidence imaging, optical ghost imaging and conventional microwave imaging methods were analyzed. Through the introduction of imaging systems, the features and differences among various systems such as random radiation, wavefront modulation and aperture encoding were compared, which made the development of microwave coincidence imaging easier to perceive. Finally, the future development trend of microwave coincidence imaging was summarized and prospected.