The National Institute of Information and Communications Technology, Panasonic Corporation and Hiroshima University announced the development of a terahertz (THz) transmitter. The new transmitter uses a single channel in the 300-GHz band and is able to transmit digital data at a rate higher than 100 gigabits (0.1 terabit) per second.
This technology allows data rates at least 10 times faster than that offered by the fifth-generation mobile networks (5G), which are expected to become available around 2020. A paper describing the new technology will be presented at the International Solid-State Circuits Conference (ISSCC), which will be held in San Francisco, California from February 5 to February 9, 2017.
It is expected that the THz band, a new and vast frequency resource, will be used for future ultra-high speed wireless communications. The research team has developed a transmitter that uses the frequency range from 290 GHz to 315 GHz and reaches a communication speed of 105 gigabits per second. Although this range of frequencies is currently unallocated, it falls within the frequency range from 275 GHz to 450 GHz. This range’s usage will be discussed at the World Radiocommunication Conference (WRC) 2019 under the International Telecommunication Union Radiocommunication Section (ITU-R).
The researchers demonstrated last year that using quadrature amplitude modulation (QAM) greatly enhances the speed of a wireless link in the 300-GHz band. This year, they exceeding 100 gigabits per second for the first time with an integrated circuit based transmitter, showing a six times higher per-channel data rate. The complete content of a DVD can be transferred in a fraction of a second at this data rate.
Professor Minoru Fujishima from the Graduate School of Advanced Sciences of Matter, Hiroshima University explained that this year, the team developed a transmitter that has 10 times more transmission power than the previous version had. This enabled them to achieve a per-channel data rate above 100 Gbit/s at 300 GHz.
Fujishima added that wireless data rates are normally measured in megabits per second or gigabits per second. This new development means however that the rate is now close to terabits per second using a simple single communication channel. With fiber optics enabling ultra-high speed wired links, wireless links have been left far behind. Terahertz could also be used as ultra-high speed links to satellites, which can only be wireless. That could also significantly boost in-flight network connection speeds.
Prof. Fujishima also noted that there are many possible applications for the new technology, including ultrafast wireless links between base stations and fast download from content servers to mobile devices.
An exciting new possibility that will be made possible by terahertz wireless is high data rate minimum latency communications. As optical fibers are made of glass, the speed of light slows down in fibers. This means that fiber optics is not adequate for applications requiring real-time responses. Currently, it is a choice between ‘minimum latency’ (microwave links) and ‘high data rate’ (fiber optics). It is simply not possible to have them both. With terahertz wireless however, light speed minimum latency links supporting fiber optic data rates will become possible. The group plans to develop 300-GHz ultrahigh-speed wireless circuits further.