Coaxial line to waveguide adapter

Abstract

An adapter of a coaxial transmission line to a waveguide is provided for connecting the waveguide to a microwave circuit of coaxial lines which is formed by milling out the lines within a plate of a soft metal. The coaxial transmission lines are of rectangular, preferably square, cross-section with the outer conductors thereof being provided by the walls of the channel. The inner conductors of the coaxial lines are rod-shaped, the inner conductors also being of rectangular or square cross-section. An aperture is provided in an outer wall of the coaxial line. A stem connects with an inner conductor and passes through the aperture to extend outwardly therefrom. A waveguide is positioned with its propagation axis parallel to the stem, the waveguide enclosing the stem and being secured to the outer walls of the coaxial lines. The stem is placed adjacent the inner wall of the waveguide, but spaced apart therefrom to support a transverse electromagnetic wave. A dipole element of planar shape extends transversely of the waveguide and is secured at an edge thereof to the terminus of the stem. The dipole element launches a propagating mode of wave within the waveguide while receiving its energization from the transverse electromagnetic wave propagating along the coaxial line and along the stem.