Abstract: An antenna (10) having a top (14), a bottom (16), and a longitudinal axis (20). An outer shell (12) of electrically conductive material is provided which is coaxial with the longitudinal axis, and which includes an outer top wall (22) joining with an outer side wall (24) that extends toward the bottom of the antenna. The shell defines an interior region (18) that is filled with a dielectric material, and the shell has at least one slot (30) with opposed slot ends. Each slot extends from one opposed slot end in the side wall, and at least partially across the top wall to an opposed other slot end. A coaxial feed (32) extends from the bottom of the antenna to the top of the antenna, to convey electromagnetic energy to or from the top wall of the antenna.

Abstract: A waveguide orthomode transducer. In a first layer a turnstile junction having a main waveguide and four waveguide ports, and four hybrid tees each have an e-port, two opposed side-ports, and an h-port. The hybrid tees are ring-arranged around the turnstile junction so the waveguide ports each communicate with one h-port, so adjacent hybrid tees inter communicate with their respective side-ports, and so the e-ports form two sets of opposed e-ports. In a second layer two h-plane power dividers/combiners each have an axial-port and two opposed side-ports. The h-plane power dividers/combiners are arranged so their respective side-ports communicate with different ones of the two sets of opposed e-ports and so their axial-ports are polarization ports. This permits a single signal with two fundamental orthogonally polarized modes to enter the main waveguide and exit separated at the polarization ports vice versa.

Abstract: An antenna (10) having outer and inner sections (12, 14) of electrically conductive material and coaxial with a longitudinal axis (19). The outer section includes an outer side wall (22) extending from the bottom to join an outer top wall at the top of the antenna. The inner section includes an inner side wall extending upward from the bottom to join an inner top wall. The outer and inner sections define an interior region (32) filled with dielectric material. The outer section has at least one slotted opening (34) with opposed ends, wherein each such slotted opening extends from one end in the outer side wall, across the outer top wall, and to the opposed end in the outer side wall. The inner section including at least one feed (36) to convey electromagnetic energy into or out of said interior region of the antenna.