300 GHz bending transmission of silver/polypropylene hollow terahertz waveguide

A bendable metal/dielectric hollow waveguide for low-loss transmission of 300 GHz terahertz (THz) radiation was proposed based on polypropylene (PP) tubing materials. The PP tube has low absorption at 300 GHz and the silver reflective film grows well on the surface of the tube via simple wet chemical method. The external silver film coated PP tube constructs a leaky-type hollow waveguide structure. The PP tube acts as the waveguide substrate providing support as well as the thick dielectric layer (>100 μm) to regulate the transmission losses for low-THz frequencies. Moreover, the low loss transmission window has been shifted at 300 GHz by optimizing the wall thickness of the PP tube. The measured straight loss of the waveguide sample at 300 GHz reaches to 1.05 dB/m, and the bending loss raises to 1.34 dB/m at a bending angle of 270° and curvature radius of 15 cm.