Patent ID: 7088303

Claim:
A flat-plate antenna, having nine conductive layers stacked in a normal dimension with transverse dimensions parallel to the face of the stack, comprising: a first layer ( 11 ) having openings forming slot radiating elements arranged in groups ( 21 , 22 , 23 , 24 ), said groups arranged in a plurality of sub-arrays ( 26 ); a second layer ( 12 ) having openings forming first transverse waveguide sections ( 28 ) extending in parallel in a first transverse direction and each coupled to a group of the radiating elements ( 21 , 22 , 23 , 24 ); a third layer ( 13 ) having openings forming first normal waveguide sections ( 30 , 31 , 32 , 33 ) each coupled to one of the first transverse waveguide sections ( 28 ); a fourth layer ( 14 ) having openings forming second transverse waveguide sections ( 34 ) extending in parallel in a second transverse direction and each coupled to a plurality of the first normal waveguide sections ( 30 , 31 , 32 , 33 ) and thereby coupled to each radiating element of one of the sub-arrays ( 26 ); a fifth layer ( 15 ) having openings forming second normal waveguide sections ( 36 , 37 ) each coupled to one of the second transverse waveguide sections ( 34 , 35 ); a sixth layer ( 16 ) having openings forming third ( 38 , 39 ) and fourth ( 40 ) transverse waveguide sections, each said third transverse waveguide section coupled to one of said second normal waveguide sections ( 36 , 37 ); a seventh layer ( 17 ) having openings forming third ( 42 , 43 ), fourth ( 44 , 45 ) and fifth ( 52 ) normal waveguide sections, each said third normal waveguide section ( 42 , 43 ) coupled to a third transverse waveguide section ( 38 , 39 ) and each said fourth and fifth normal waveguide section ( 44 , 45 , 52 ) coupled to a fourth transverse waveguide section ( 40 ); an eighth layer ( 18 ) having openings forming extensions ( 60 , 61 ) of said third normal waveguide sections and extensions ( 62 , 63 ) of said fourth normal waveguide sections, and forming a fifth transverse waveguide section ( 66 ) coupling said fifth normal waveguide sections ( 51 – 58 ) to a common feed point ( 68 ); a ninth layer ( 19 ) having openings forming extensions ( 70 , 71 ) of said third normal waveguide sections and extensions ( 72 , 73 ) of said fourth normal waveguide sections, and forming sixth normal waveguide section ( 76 ) coupled to said common feed point ( 68 ); and a support layer ( 20 ) suitable to support at least one signal processing unit with coupling access to said third and fourth normal waveguide section extensions ( 70 – 73 ) and to support an antenna port with coupling access to said sixth normal waveguide section ( 76 ).