Abstract: With the development of wireless communication, the 6G mobile communication technology has received wide attention. As one of the key technologies of 6G, terahertz (THz) communication technology has the characteristics of ultra-high bandwidth, high security and low environmental noise. In this paper, a THz duplexer with a half-wavelength coupling structure and a sub-harmonic mixer operating at 216 and 204 GHz are designed and measured. Based on these key devices, a 220 GHz frequency-division multiplexing communication system is proposed, the real-time data rate of which is 10.4 Gbit/s for one channel and the transmission distance is 15 m. The measured constellation diagram of two receivers is clearly visible, the signal-to-noise ratio (SNR) is higher than 22 dB and the bit error ratio (BER) is less than 10-8. Furthermore, the high definition (HD) 4K video is also transmitted in real time without stutter.
Keywords: frequency-division multiplexing; sub-harmonic mixer; terahertz communication; terahertz duplexer