Abstract: A dual band multimode coaxial antenna feed has an inner section of longitudinal hollow waveguide having first and second orthogonal mode transducers that interface first and second orthogonally polarized cylindrical waveguide TE11 mode signals lying in a first upper (e.g., Ka) frequency band. An outer coaxial waveguide section has a Potter horn surrounding the inner waveguide section, which terminates at a polyrod. The outer section includes third and fourth orthogonal mode transducers that interface orthogonally polarized coaxial waveguide TE11 mode signals lying in a second lower (e.g., X) frequency band. A tracking port coupled to the outer coaxial waveguide section provides an output representative of the difference pattern of the radiation profile produced by transverse electromagnetic TEM mode signals generated and propagating in the outer coaxial waveguide. A mode suppressor in the outer waveguide section adjacent its two orthogonal mode transducers locally suppresses TEM signals in their vicinity.

Abstract: This disclosure deals with a three-element unit array (or stacked groups of the same) that enables the use of very large length-to-diameter dipole elements to cover broad frequency bands, greater than 2:1 in frequency ratio, by novel feed structures exciting the element gaps.

Abstract: This disclosure deals with a three-element unit array (or stacked groups of the same) that enables the use of very large length-to-diameter dipole elements to cover broad frequency bands, greater than 2:1 in frequency ratio, by novel feed structures exciting the element gaps.