Common antenna aperture having polarization diversity

Claim 1

A common aperture for a dual polarized microwave antenna system having a common reflector and a first slotted waveguide section emitting electromagnetic energy of a first type polarization and a second slotted waveguide section emitting electromagnetic energy of a second type polarization, said aperture comprising in combination: a first and a second microwave aperture section located in mutually spaced apart relationship in relatively close proximity to said first and second waveguide sections and wherein energy of said first and second type polarization is adapted to be directed in a common path therebetween to said reflector; each said first and second aperture section being further characterized by, a. a body portion having an outer surface directed toward said reflector and an inclined surface Adjacent said outer surface, said inclined surface diverging outwardly from said common path, b. a plurality of beamwidth compensating means located on said inclined surface, each said means having a first and a second intersecting surface, said first surface being substantially coplanar with said outer surface of said body portion, and said second surface being directed along the direction of said common path, and c. sidelobe suppression choke means located on said outer surface, whereby substantially identical CSC2 cos1/2 primary radiation patterns of first and second type polarization which when reflected from said reflector produce substantially identical primary radiation patterns of said first and second type polarization and a polarization insensitive secondary pattern.