Identification of several propagation regimes for terahertz surface waves guided by planar Goubau lines

We report on the experimental and numerical characterization of planar Goubau lines in the terahertz frequency range. We demonstrate the existence of three propagation regimes that depend on the ratio between the thickness of the dielectric slab and the operation wavelength. Although two of these regimes are dispersive, it is possible to mitigate this undesirable property by a judicious choice of the materials used to fabricate the structures. As an example, we show that Au planar Goubau lines supported by thin layers of Kapton have very interesting characteristics including a modest dispersion coefficient (0.28 ps/mm) and low losses (<0.4mm(-1)) up to 0.8 THz. (c) 2013 AIP Publishing LLC.