Huygens' Metasurfaces for Extending the Scan-range of Phased arrays

In this overview paper we summarize our results regarding the problem of extending the angular scan range of antenna arrays using Huygens' lens-like metasurfaces. Existing theory of scan enhancement using lenses is summarized, where various devices are discussed. This includes the single-lens far-field enhancer, the single-lens near-field enhancer and finally the two-lens near-field enhancer. An important addition to existing work is that physical metasurface structures are full-field simulated. Extremely close agreement between simulated and theoretical results is observed despite non-idealities such as losses which are present in the simulations.