Antenna for transmitting circularly polarized television signals

An antenna for circularly polarized television transmission comprising,

• an elongated coaxial waveguide having inner and outer conductors,
• the outer conductor of said waveguide having a multiplicity of slots spaced along the length and around the circumference of the outer conductor for radiating horizontally polarized energy,
• a multiplicity of dipoles mounted on the outer surface of said outer conductor and spaced along the length and around the circumference of the outer conductor for radiating vertically polarized energy,
• each of said dipoles being disposed in relation to said slots so that the combination of the horizontally and vertically polarized radiation produces circularly polarized radiation,
• first coupling means for coupling electromagnetic energy from the interior of said waveguide to said slots and including means for feeding electromagnetic energy directly from the interior of said waveguide to said slots, and
• second coupling means for coupling electromagnetic energy from the interior of said waveguide to said dipoles independently of said first coupling means and including an internal probe and an external transmission line associated with each of said dipoles for feeding electromagnetic energy from the interior of said waveguide to said dipoles.

An antenna for circularly polarized television transmission comprising,

• an elongated coaxial waveguide having inner and outer conductors,
• the outer conductor of said waveguide having a multiplicity of slots spaced along the length and around the circumference of the outer conductor for radiating horizontally polarized energy,
• a multiplicity of dipoles mounted on the outer surface of said outer conductor and spaced along the length and around the circumference of the outer conductor for radiating vertically polarized energy,
• each of said dipoles being disposed in relation to said slots so that the combination of the horizontally and vertically polarized radiation produces circularly polarized radiation, and
• first coupling means for coupling electromagnetic energy from the interior of said waveguide to said slots, and
• second coupling means for coupling electromagnetic energy from the interior of said waveguide to said dipoles and including:
• a plurality of probes extending into said waveguides at intervals along the length thereof, a trough transmission line formed by a pair of longitudinal ribs on the exterior surface of said outer conductor, and a plurality of external conductors, disposed between said ribs, for respectively connecting one of said probes to one of said dipoles.

An antenna for circularly polarized television transmission comprising,

• an elongated coaxial waveguide having inner and outer conductors,
• the outer conductor of said waveguide having a multiplicity of slots spaced along the length and around the circumference of the outer conductor for radiating horizontally polarized energy,
• a multiplicity of dipoles mounted on the outer surface of said outer conductor and spaced along the length and around the circumference of the outer conductor for radiating vertically polarized energy,
• each of said dipoles being disposed in relation to said slots so that the combination of the horizontally and vertically polarized radiation produces circularly polarized radiation, and
• first coupling means for coupling electromagnetic energy to said slots, and
• second coupling means for coupling electromagnetic energy to said dipoles and being separate and independent of said first coupling means,
• each of said coupling means being at least partially disposed within said waveguide and picking up electromagnetic energy from the interior of said waveguide in a common transverse plane.