An assortment of standard waveguide components, from an advertisement by De Mornay - Budd Inc., New York, in a 1947 electronics magazine. Waveguide is used to conduct microwave radio waves from place to place. Microwaves are used in data networking links, communications satellites, satellite TV, radar, and microwave ovens. A waveguide is a conductive metal "pipe" that confines the microwaves.