Dynamic Sub-THz Radio Channel Emulation: Principle, Challenges, and Experimental Validation

Sub-terahertz (Sub-THz) technology, as one of the key candidates for the six generation (6G) systems, has attracted increasing attention from academia and industry, due to its promise to unleash vast amounts of new frequency spectrum. Sub-THz system designs pose unique and more challenging circumstances compared to traditional communication systems. These challenges arise from the demanding propagation conditions, limited availability of commercial radio frequency (RF) components, the need for high-gain and beam-steerable antennas that are highly integrated at both ends of the communication link, short-range communication scenarios, and the requirement for extreme data rates. Therefore, it is crucial to assess the performance of radio devices in realistic propagation channels in sub-THz communication systems. In this work, we present the concept, challenges, and enabling solutions for achieving sub-THz radio channel emulation. Moreover, we experimentally demonstrated the reconstruction of the measured propagation channels at 140 GHz with a commercial radio channel emulator in the laboratory. The developed dynamic fading channel replay concept and experimental validation procedure allows initial tests of future sub-THz communication devices.