Waveguide fence support

A method of making a waveguide for a radar system comprising:

• forming an additive manufacturing build of a waveguide by forming an initial layer, followed by forming a succession of build layers on the initial layer in a build direction from the initial layer towards a final layer, wherein forming the succession of build layers includes forming an overhanging feature supported by a support formed in the succession of build layers,
• wherein the additive manufacturing build is a radar waveguide, and wherein the overhanging feature is a fence across an electromagnetic (EM) wave passage that extends in the build direction, wherein forming the support includes building the support up in successive layers from an initial support layer to a final support layer that contacts a first layer of the fence, followed by removing the support from the fence in the EM wave passage.