CASSEGRAINIAN AXIAL-SYMMETRY ANTENNA Russian patent published in 1995 - IPC

FIELD: antenna equipment. SUBSTANCE: antenna feed in the form of horn and impedance cylindrical extension piece with quarter-wavelength grooves in inner surface allow axial-symmetry pattern with steep declivities and stable position of phase center to be formed. Its position does not depend on distance to points of reflection of beams from auxiliary reflector within fixed intervals of distance between aperture plane of antenna feed and center of auxiliary reflector. If this distance is less than length of wave then auxiliary reflector has parabolic shape and if it is bigger than two lengths of wave than auxiliary reflector has elliptical or hyperbolic shape. Description of invention specifies various variants of make of horn part and impedance extension piece (with ring or spiral grooves). EFFECT: enhanced efficiency of Cassegrainian axial-symmetry antenna with mixed focal plane, improved cross-polarization discrimination with minimization of antenna feed. 3 cl, 2 dwg