Formed waveguide antennas using one or metal sheets can improve the materials and manufacturing process of a radar assembly. For example, the radar system can include a printed circuit board (PCB) and a metal sheet attached to the PCB. The metal sheet can be formed to provide multiple waveguide antennas that each include multiple waveguide channels. Multiple radiation slots can be formed on a surface of each of the multiple waveguide channels. The PCB can include an MIMIC and a thermally conductive material covering a portion of a first and a second surface of the PCB. The metal sheet can also be formed to provide a shield for the MIMIC. In this way, the described techniques and systems permit the waveguide antennas to formed with materials and a manufacturing process that reduce costs while still providing high performance (e.g., minimized loss).