Waveguide is a technology uniquely synonymous with high-frequency RF/microwave electronics. Described simply, it is a form of hollow conductive metal tube that carries energy from one point to another. For RF/microwave use, it handles electromagnetic (EM) energy; forms of waveguide have also been used to carry acoustical and optical energy. Waveguide can be used to fashion a wide range of RF/microwave and even millimeter-wave components, including transmission lines, couplers, power dividers, and filters.