A Metasurfaced Pyramidal Horn Antenna for Circularly-Polarized Applications

Abstract

A high-gain circularly-polarized pyramidal horn antenna is developed by loading a thin metasurface linear-tocircular polarization (LP-CP) converter on the aperture of a standard pyramidal horn. The LP-CP converter is composed of two identical dielectric slabs, sandwiched by three subwavelength metallic element arrays. By placing the metasurface LP-CP converter on the aperture of a standard horn antenna, the linearly-polarized wave emitted by the horn can be converted to be circularly-polarized, without changing much other radiation performance. An example is given of a metasurface LP-CP converter and horn (metahorn) antenna that exhibits high gain and circular polarization. The measurement of this metahorn shows a 3-dB axial ratio bandwidth of 8.7%, with a maximum gain reduction of 2 dB, compared with that of the original airfilled standard pyramidal horn.