Flexible PTFE hollow dielectric waveguides for terahertz applications: analysis and experimental study

In recent years, terahertz technology has developed rapidly, and one of the important topics is low-loss, flexible, and low-cost terahertz waveguides. In this paper, PTFE tubes are used as hollow terahertz dielectric waveguides with an operating frequency of up to 500 GHz. Using numerical analysis and simulation, transmission properties such as transmission loss and bending loss are discussed. In particular, special attention is given to the impact of deformation caused by compression during use on transmission performance. To validate our analysis, we fabricated PTFE tubes with an inner diameter of 0.3 mm and an outer diameter of 0.6 mm as well as the corresponding mode converters, which were measured in the 325-500 GHz frequency range. The measured transmission loss was less than 16.6 dB/m, and the bending loss was less than 2 dB/Turn.