THz Radio Communication: Link Budget Analysis toward 6G

How well do upper millimeter-wave and terahertz frequency bands enable wireless communications? In this work, we approximate the current and estimate the future communication potential with emphasis on antenna and radio frequency hardware technologies, and radio propagation challenges. This is done by performing link budget evaluations with justified estimates of link budget calculus terms, such as the achievable or required noise figure, transmit power, and antenna gain. Estimates are based on current enabling technologies and needs to advance those. From the RF viewpoint, the bottlenecks are in generating sufficiently high transmit power and low noise with the support of very high antenna gains. As an example, we discuss opportunities around 300 GHz frequency. Challenges to support 100 Gb/s bit rate at 30 GHz bandwidth on 10 m link distance is analyzed for different kinds of devices.