Three-dimensional horn air waveguide antenna made with formed and brazed metal sheets

A method of manufacturing a three-dimensional (3D) horn air waveguide antenna assembly, the method comprising:

• forming a bottom metal layer;
• forming a first top metal layer arranged atop the bottom metal layer and including a first side and a second side, the first top metal layer defining a slot area;
• and
• forming a second top metal layer arranged atop the first top metal layer, the second top metal layer defining at least a portion of a horn air waveguide antenna area,
• wherein the bottom metal layer, the first side of the first top metal layer, and the second side of the first top metal layer at least partially define a channel area,
• wherein the slot area defines a first width and the channel area defines a second width greater than the first width,
• wherein the channel area is disposed between the bottom metal layer and the slot area, and
• wherein the slot area fluidly connects the channel area and the horn air waveguide antenna area.