Platformed post arrays for waveguides and related sensor assemblies

Waveguides and related assemblies for use, for example, in RADAR sensor assemblies and the like. In some embodiments, the waveguide may comprise a conductive member having a first plurality of posts arranged in a first row thereon. A second plurality of posts may be arranged in a second row on the conductive member to define a waveguide between the first plurality of posts and the second plurality of posts. One or more platforms may be provided to project at least a subset of the first plurality of posts and the second plurality of posts beyond at least a portion of the conductive member adjacent to the one or more platforms. A second conductive member, such as a cover, may be coupled to the conductive member such that the first and second pluralities of posts extend between the conductive member and the cover.