Terahertz Channel Characterization Using a Broadband Frequency Comb Radiator in 130-Nm SiGe BiCMOS

The terahertz (THz) band has opened up a new frontier for high-speed, wireless communication, high-resolution radars, and highly precise remote sensing. Identifying the low-loss atmospheric windows is vital for these applications. In this study, a long-path THz communication channel is characterized in the frequency range of 0.32-1.1 THz using a custom, silicon-based THz pulse radiator chip. The chip radiates 1.7-ps pulses via an on-chip antenna at a repetition rate of 8 GHz, resulting in a broadband 0.1-1.1 THz frequency comb. It is fabricated in 130-nm SiGe BiCMOS process and consumes 45 mW of dc power. A specular link was created using the impulse radiator, parabolic reflector antennas, a plane mirror, and a downconverter mixer. The THz channel was characterized up to a distance of 110 m. The measurement results demonstrate channel path loss, atmospheric absorption, and low-loss frequency windows suitable for wireless links in the THz range. The results correspond well with the HITRAN database [1].