Wideband Characterization of 3D Printed THz Rectangular Dielectric Waveguides by THz Frequency-Domain Spectroscopy

In this paper single-mode dielectric waveguides for 140 GHz are designed and fabricated by 3D printing technology. The waveguides are simulated using the finite difference time domain method and characterized by determining their frequency-dependent attenuation constant and frequency-dependent effective refractive index from 100 GHz to 180 GHz using THz frequency-domain spectroscopy. Furthermore, the mode patterns at different frequencies are observed by performing transversal scans of the far-field radiation pattern at the output of the waveguide.