The radar system includes a split-block assembly comprising a first portion and a second portion. The first portion and the second portion form a seam, where the first portion has a top side opposite the seam and the second portion has a bottom side opposite the seam. The system includes at least one port located on a bottom side of the second portion. Additionally, the system includes radiating elements located on the top side of the first portion, wherein the radiating elements are arranged in a plurality of arrays. Yet further, the system includes a set of waveguides in the split-block assembly configured to couple each array to at least one port. Furthermore, the split-block assembly is made from a polymer and where at least the set of waveguides, the at least one port, and the plurality of radiating elements include metal on a surface of the polymer.