Patent ID: 7423603

Claim:
An apparatus comprising: (a) a round cylindrical waveguide having a flat closed end substantially perpendicular to the axis of said round cylindrical waveguide and an open end; (b) a waveguide shorting probe substantially the diameter of said round cylindrical waveguide spaced substantially parallel to said flat closed end at substantially one-quarter wavelength from said flat closed end and located within said round cylindrical waveguide and connected at each end to said round cylindrical waveguide, said waveguide shorting probe being at a third orientation; (c) a first probe shorter than the diameter of said round cylindrical waveguide spaced substantially parallel to said flat closed end at substantially one-half wavelength from said flat closed end and extending within said round cylindrical waveguide and one end not connected and one end connected to a first feed line, said first probe being at a first orientation; (d) a second probe shorter than the diameter of said round cylindrical waveguide spaced substantially parallel to said flat closed end at substantially three-quarters wavelength from said flat closed end and extending within said round cylindrical waveguide and one end not connected and one end connected to a second feed line, said second probe being at a second orientation; (e) wherein said second orientation and said third orientation are the same orientation, and said first orientation is substantially quadrature to said same orientation; (f) wherein said round cylindrical waveguide is substantially three-quarters wavelength in length; and the apparatus (a) through (f) being denoted a circular horn and the apparatus comprising two or more said circular horns positioned substantially in a stacked arrangement wherein all of said circular horns first orientation are in a same direction.