Peripherally Excited Phased Array Architecture for Beam Steering with Reduced Number of Active Elements

An electronically scannable phased array antenna architecture is proposed with a drastically reduced number of active antenna elements. The proposed approach is based on the concept of Huygens’ metasurfaces, where the fields in a given region are controlled by active or passive electromagnetic sources on the boundary surface of this region. Using this approach, arbitrary plane waves are excited inside a metallic cavity by peripheral sources, and the cavity is engineered to radiate a single or multiple pencil beams through appropriately perforated slots on its top surface. The proposed peripherally excited (PEX) phased array architecture generates pencil beams that are electronically scanned by controlling the amplitudes and phases of the peripheral sources. The proposed concept has the potential to drastically reduce the required number of active elements in 2-D phased arrays without compromising directivity. However, the possible beam-pointing directions are constrained.