Technology developed in the pursuit of fusion energy has had an impact in many other industries. The requirements being met by advanced microwave and millimeter wave components for fusion applications can open up whole new areas in emerging industries. For plasma heating, microwave components such as waveguide, switches, and polarizers, are being built which can withstand megawatts of sustained power at frequencies up to 170 GHz. In microwave-based diagnostics for fusion systems, enormous frequency bandwidths such as 35–170 GHz are possible for transmission lines at very high propagation efficiency (