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

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 λ/20 and λ/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.