Low-loss surface-wave propagation on coated or uncoated cylindrical conductor from 0.1 to 1 THz

Abstract Surface-wave propagation on coated or uncoated conducting wires, rods, or tubes has been shown to provide low attenuation, moderate field extent, low dispersion, and high power-handling at frequencies from 100 GHz to 1 THz. Typical conductors are copper, aluminum, or stainless steel. Uncoated conductors provide the lowest loss, while conductors coated with a thin layer of low- loss dielectric (such as Teflon, polystyrene, or polyethylene) have the smallest field extent. The guided mode is the TM₀₁, often referred to as the Sommerfeld mode. The properties of the guided wave have been theoretically analyzed and measured results were obtained at 105 and 140 GHz. In the last two years four different research groups have reported new results. While the earlier work was conducted in the search for long, low-loss transmission lines (100 meters to 1 kilometer), the current applications are for lengths about 1 meter long, as might be used in probes. The recent results will be summarized, and an optimized design will be present, along with general curves of attenuation, field extent, and power handling capability from 100 GHz to 1 THz.