Surface Waves and Their Application to Transmission Lines

Abstract

In this paper the applicability of non-radiating surface waves for transmission lines is investigated. Two types of waves are considered. The first one, originally studied by A. Sommerfeld, is guided by a cylindrical conductor of finite conductivity. Although this wave type has (under comparable conditions) much lower attenuation than the waves in coaxial cables or rigid wave guides, its practical application is restricted by the fact that the extension of the field is very large. Efficient excitation and undisturbed propagation of this wave mode are feasible only for very high frequencies. The other wave type considered in this paper has not been treated in the literature. It is guided by a conductor which is coated with a dielectric layer or the surface of which is otherwise modified; for example, by being threaded. The field of this wave type has a structure similar to that of Sommerfeld's wave, but the extension of the field can be controlled by the surface modification. Thus low loss transmission lines on the basis of this wave type become feasible for frequencies above 100 megacycles. The information necessary for the design of such lines is given and the agreement between the theoretically expected transmission losses and the measured transmission losses is checked.

Frequency-dependent radiation patterns emitted by THz plasmons on finite length cylindrical metal wires

“…These simulations were designed and conducted using COMSOL Multiphysics, a commercially available finite element method modeling software. These calculations, based on the finite element method (FEM), simulate the propagation of a Sommerfeld wave [15] along a wire waveguide. A 0.9 mm diameter waveguide, 2.5 cm long, is placed inside of a cylindrical domain (3.75 cm in length, 6.5 mm in diameter) that bounds the volume of the simulation.…”

Light scattering under nanofocusing: Towards coherent nanoscopies

“…Multidimensional correlation spectroscopies [69] may also be implemented at the nanoscale in this way, without the need for hybrid approaches [70]. Lastly, we wish to point out that these ideas may also be pursued in the infrared spectral range using surface phonon-polaritons [71] or at THz and lower frequencies using spoof SPPs [72,73].…”

THz Sommerfeld wave propagation on a single metal wire

“…This type of guided propagation does not occur with a perfect conductor. 8 The principle mode ͑the Sommerfeld wave͒ of such a structure has remarkably low loss and low group velocity dispersion, while all other modes vanish almost immediately upon excitation due to their high attenuation. 6 Recently, observations of THz pulses propagating on single metal wires have been reported, 11,12 which showed very low loss and low group velocity dispersion.…”

“…5 Single metal wires have been theoretically and experimentally studied for guided propagation of electromagnetic waves from tens of meters to millimeter waves. [6][7][8][9][10] On a cylindrical conductor ͑wire͒, electromagnetic waves propagate as weakly guided surface waves, due to the finite conductivity of the metal. This type of guided propagation does not occur with a perfect conductor.…”