Patent ID: 6320554
Filing Date: 2001-11-20
Classification: H01Q

Abstract:
A feed horn comprising a waveguide of a circular section and a horn portion, said horn portion having a base end connected to said waveguide and being expanded in a horn shape from said base end toward a front end to define an elliptic open end, the base end being provided with a cylindrical elliptic tapered portion having one end forming a circular shape and an opposite end forming a elliptic shape,wherein a plurality of elliptic ridges extending in parallel toward said open end are formed in the shape of concentric ellipses on an inner slant peripheral surface of said horn portion in such a manner that the spacing between two adjacent said ridges is equal throughout the whole circumferences of the ridges and that a virtual plane formed by connecting tip ends of said ridges is in a horn shape along the inner slant peripheral surface of said horn portion.