US Patent 7221329 Enhanced beam antenna

A reflector includes a conductive surface and a surface coating. The surface coating includes a binder and metal oxide grains embedded in the binder. The metal oxide grains include aluminum oxide that constitute up to 60% of the metal oxide by weight. A method of making a reflector includes forming a slurry, applying an electric field between a spray gun nozzle and the reflector, and spraying the slurry through the spray gun nozzle onto the reflector. The slurry contains metal oxide grains suspended in a binder.