Computational imaging using frequency-diverse metasurfaces

This paper summarizes the recent advances in using frequency-diverse metasurfaces for computational imaging in the microwave and millimeter wave regimes. Frequency-diverse apertures are defined as structures that can generate distinct radiation patterns as a function of frequency. Such waveforms can multiplex a scene information into a set of backscattered measurements, which can be decoded using computational algorithms. In this manner, these apertures can retrieve a scene's reflectivity map using a fast frequency sweep (all-electronic operation), circumventing the requirement for a mechanical scan or active circuit components. We review recent advances in developing these apertures and examine their performance in both simulation and experimental settings. Finally, efforts to build large apertures, which can image at the diffraction limit, are discussed.