Beam Steering for Long-Distance Sub-THz Links Using a Lens-Integrated Leaky-Wave Antenna

This paper presents the first long distance beam-steering sub-THz wireless link for high-speed data transmission to single or multiple users via digital spectrum allocation. We demonstrate a single beam steered to a user at 25 m with data rates of up to 40 Gbit/s over a wide steering range. Additionally, we present a dual-user link enabled by digital subcarrier generation, achieving an aggregate data rate of 80 Gbit/s (40 Gbit/s per user) over a 16 m distance. Broadband optically generated subcarriers are downconverted to sub-THz frequencies via a uni-traveling-carrier photodiode. A lens-integrated leaky-wave antenna transmits the sub-THz signals, providing up to 30 dBi gain and 55° beam-steering range in the 220-330 GHz band. The signal is received using one or two all-electronic receivers operating in the 280-320 GHz range. This proof-of-concept experiment provides key insights into high-data rate 6G networks at sub-THz frequencies, serving as a guideline for future system design.