Far-Field Super-Resolution Imaging With Compact and Multifrequency Planar Resonant Lens Based on Time Reversal

Abstract

Planar resonant lenses (PRLs) consisting of periodically distributed strip resonators with different lengths are proposed for far-field super-resolution electromagnetic imaging. With the help of PRLs, evanescent waves can be converted into propagation waves. So, based on time-reversal (TR) technique, time-reversal mirror in the far-field can receive the electromagnetic signals carrying the subwavelength information. Experiments are performed to validate the proposed method in laboratory environment at microwave band. Far-field super-resolution imaging results with resolutions of ${\lambda }/{20}$ and ${\lambda }/{10}$ , respectively, are obtained, well beyond the diffraction limit. The compact size and multifrequency property of the proposed PRLs will make them easily be integrated to new super-resolution imaging systems.