Novel Planar Antennas Using Circular, Curved and Straight Gratings for Conical-Sector Beam Patterns

Abstract

Planar antennas that utilize surface-waves (SWs) for leaky-wave (LW) excitation are investigated. Specifically, Yagi-Uda like surface-wave launchers (SWLs) are utilized as the antenna feed, exciting cylindrical SWs on a grounded dielectric slab. With the addition of circular, curved or straight metallic strip gratings, suitable conditions for LW field excitation are achieved. Essentially, the SWL and grating configurations can generate cylindrical LW field distributions within a confined region on the guiding surface. Such aperture fields can produce pencil and conical-sector beam patterns in the far field.