US Patent 9455495 Two-dimensionally electronically-steerable artificial impedance surface antenna

An apparatus comprising a plurality of radiating elements and a plurality of surface wave feeds. Each radiating element in the plurality of radiating elements comprises a number of surface wave channels in which each of the number of surface wave channels is configured to constrain a path of a surface wave. A surface wave feed in the plurality of surface wave feeds is configured to couple a surface wave channel in the number of surface wave channels of a radiating element in the plurality of radiating elements to a transmission line configured to carry a radio frequency signal.