A leaky waveguide antenna array that receives and/or transmits electromagnetic signals includes a plurality of radiation waveguides disposed in parallel to each other on a surface plane to form the antenna array. A feed waveguide is located below the surface plane and provides an electromagnetic signal to the plurality of radiation waveguides and/or receives a plurality of electromagnetic signals from the plurality of radiation waveguides and provides a composite electromagnetic signal at an output of the feed waveguide. Each of the plurality of radiation waveguides has a waveguide axis and includes a plurality of apertures arranged in a direction of the waveguide axis. The feed waveguide includes a first section of waveguide having a first end connected to an input/output port. The first section of waveguide has a height substantially the same as the height of each of the plurality of radiation waveguides and the first section of waveguide has a second end coupled to a first junction point. The first junction point transitions from the first section of waveguide to a second section of waveguide and a third section of waveguide that each have a height that is substantially half of the height of the first section of waveguide. The second section of waveguide transitions with an upward sloping ramp to the substantially half height of the first section of waveguide. The third section of waveguide transitions with a downward sloping ramp to the substantially half height of the first section of waveguide. The third section of waveguide is substantially a mirror image of the second section of waveguide. The feed waveguide also includes a septum connected to vertical walls of the first, second and third sections of waveguide which aids in the transition from the height of the first section of the waveguide to the height of the second section and the third section of waveguide. Each of the second section of waveguide and the third section of waveguide are coupled to a corresponding first signal port and second signal port of the feed waveguide. Each of the first signal port and the second signal port are coupled to a corresponding one of the plurality of radiation waveguides.