The planar Goubau line is a promising low-loss metal waveguide for terahertz interconnects. To enable advanced system architectures and multi-port measurements based on planar Goubau lines, there is a strong need for broadband impedance-matched loads, which can be used to absorb the energy and minimize standing waves in a system. In this work, we propose a matched load for planar Goubau lines based on an exponentially-tapered corrugated line, gradually increasing conductor losses while maintaining small reflections. The corrugation density is high enough to increase conductor losses without requiring an auxiliary low-conductivity material, simplifying the fabrication process. A 400-μm long planar Goubau line load was fabricated on a 10-μm thick silicon substrate suspended in the air. Electromagnetic simulations of the load show excellent agreement with calibrated reflection measurements in the frequency range 0.5 THz - 1.1 THz. Above the cut-off frequency of around 580 GHz, the measured reflections are much less than -19 dB, below the noise floor of the characterization setup.
@article{arxiv.2210.11847,
title = {A corrugated planar-Goubau-line termination for terahertz waves},
author = {Juan Cabello-Sánchez and Vladimir Drakinskiy and Jan Stake and Helena Rodilla},
journal= {arXiv preprint arXiv:2210.11847},
year = {2023}
}