Why choose THZ frequency band for 6G?

Dec 25,2024
15 VIEWS

6G is currently in a very early stage of research. The vision of "Network 2030" expected by the International Telecommunication Union is gradually being realized. Although the industry is still a few years away from entering the 6G standard development process, sub THz technology in the Asia Pacific region has become a focus of research.

A key goal and active research area of 6G is to achieve a data throughput of 100 Gbps to 1 Tbps. This extreme data throughput may eventually become a key performance indicator (KPI) for 6G. However, whether from the perspective of RF or baseband, this goal will bring significant challenges.

For millimeter wave applications in 5G communication, taking the 28GHz frequency band as an example, the available channel bandwidth is only 1GHz. Terahertz operates around the frequency of 1THz, which is several times higher than millimeter waves. The higher the frequency, the greater the potential available bandwidth. The potential operating bandwidth of terahertz waves is at least one order of magnitude higher than millimeter wave heights.

In addition, terahertz waves also have other characteristics suitable for communication. For example:

Another characteristic of terahertz waves is that the signal-to-noise ratio of the time-domain spectrum is very high. Therefore, according to Shannon's theorem, using terahertz waves for data transmission can achieve much higher data transmission rates than millimeter waves due to their higher channel bandwidth and signal-to-noise ratio.

Secondly, due to the transition from electronics to photonics, terahertz waves possess the advantages of both microwave communication and optical communication. In addition to having a faster transmission speed than microwaves, it also has the characteristics of narrow beam and good directionality, which can achieve better transmission security and anti-interference ability.

Thirdly, due to the wavelength of terahertz waves being only 0.03mm to 3mm, the antennas of terminal devices can be made very small, greatly saving device design space. The number of antennas can also be further increased, providing conditions for the implementation of high-order MIMO.

Fourthly, NTN is a crucial component of 6G mobile communication, and the terahertz frequency band is particularly suitable for satellite communication. In a vacuum environment, the data throughput of terahertz wave communication is over a thousand times faster than current ultra wideband technology. China launched a 6G communication test satellite in 2020, equipped with terahertz satellite communication equipment, which can establish data transmission and reception links on the satellite and conduct terahertz communication experiments.

Fifth, due to its undeveloped nature, the terahertz band has abundant frequency resources and is easy to utilize in the future.

Due to the above characteristics, terahertz waves may become a key component of 6G communication systems.