A terahertz (THz) transmitter chip capable of signal transmission at a per-channel data rate of over 10Gbps over multiple channels at around 300GHz has been developed by Hiroshima University, the National Institute of Information and Communications Technology, and Panasonic Corporation.
The aggregate multi-channel data rate exceeds 100Gbps. This technology could data rates ten times higher than current technology allows.
The THz band is a new and vast frequency resource with wide available bandwidths and frequencies even higher than millimeter-wave WLAN (from 57GHz to 66GHz). However, its not currently exploited for wireless communications. Since the speed of a wireless link is proportional to the bandwidth in use, THz is ideally suited to ultrahigh-speed communications.
The transmitter spans 275 GHz to 305 GHz, which is currently unallocated, and its future frequency allocation is to be discussed at the World Radiocommunication Conference (WRC) 2019 under the International Telecommunication Union Radiocommunication Sector (ITU-R).
Most wireless communication technologies use lower frequencies (5GHz or below) with high-order digital modulation schemes, such as the quadrature amplitude modulation (QAM), to enhance data rates within limited bandwidths available. The research group has successfully demonstrated that QAM is feasible at 300GHz with CMOS and that THz wireless technology could offer a serious boost in wireless communication speed.
“Now THz wireless technology is armed with very wide bandwidths and QAM-capability. The use of QAM was a key to achieving 100 gigabits per second at 300 GHz,” said Prof. Minoru Fujishima from Hiroshima University.
“Today, we usually talk about wireless data-rates in megabits per second or gigabits per second. But I foresee we’ll soon be talking about terabits per second. That’s what THz wireless technology offers. Such extreme speeds are currently confined in optical fibers. I want to bring fiber-optic speeds out into the air, and we have taken an important step toward that goal,” he added.
“We plan to develop receiver circuits for the 300GHz band as well as modulation and demodulation circuits that are suitable for ultrahigh-speed communications,” said Prof. Fujishima.
The research group plans to further develop 300GHz ultra high-speed wireless circuits.