Abstract: A planar slot antenna grid contains a number of waveguide-slot radiators having wide reverse side and wide outer side faces in which there are obtained, respectively, exciting slots of coupling and radiating slots. The faces lie correspondingly in two parallel planes, and a waveguide-feeder network is formed by waveguide distributors of power and feeding waveguides. Channels of the waveguides communicate with the exciting slots of coupling. The waveguide-slot radiators represent strip-line waveguides including a common dielectric substrate. The reverse side of the substrate is covered by a metallized coating serving as a common wide reverse side face of the waveguide-slot radiators. Each wide outer side face of the radiators represents a strip-line made of alternating narrow and wide segments formed on the outer side face of the dielectric substrate.