Nav: Home

World's-first compact transceiver for terahertz wireless communication using 300-GHz band

June 09, 2016

Nippon Telegraph and Telephone Corporation (NTT; head office: Chiyoda-ku, Tokyo; president & CEO: Hiroo Unoura), Fujitsu Limited (Fujitsu; head office: Minato -ku, Tokyo; president & CEO: Tatsuya Tanaka), and the National Institute of Information and Communications Technology (NICT; head office: Koganei city, Tokyo; president: Masao Sakauchi) have cooperatively developed the world's-first compact terahertz wireless transceiver using the 300-GHz band and experimentally demonstrated that it can transmit data at transmission rate of 40 gigabits per second through multiplex transmission using orthogonal polarization. Since the transceiver can assure a broad frequency band, it is expected to be applied for high-speed wireless communication. Moreover, in the present development, under a supposed usage case in which large-capacity contents are downloaded from an information terminal (such as downloading video and music), the transmitter of the developed transceiver was installed in such an information terminal. Moreover, according to the results of a contents-downloading experiment using a compact (i.e., smartphone-sized) terminal fitted with a matching developed receiver, data transmission of two gigabytes per second (namely, downloading at a rate of one DVD's worth of data in about three seconds) was achieved. Through this experiment, it was shown that a compact transceiver using terahertz waves in the 300-GHz band--as well as the accompanying elemental circuit technology--could achieve large-capacity transmission. From now onwards, it is expected that technologies utilizing terahertz waves in the 300-GHz band will make major advances. The developed technology was presented in detail at IMS2016 (2016 IEEE MTT-S International Microwave Symposium) held in San Francisco from May 22nd, 2016.

1 Background

As broadband networks continue to spread, investigations on high-speed data transmission via wireless communication are progressing across the world. To attain transmission rates at the level of the several-dozen gigabits per second (which will enable uncompressed realtime wireless transmission of ultra-high-definition images and instantaneous transfer of large-capacity data), it is necessary to utilize presently unused frequency bands. In particular, it is necessary to develop a compact wireless device that can handle high-speed data transfer. Terahertz wireless communication is a promising technology for meeting that need, and utilization of the 300-GHz band (which is presently unused by industry) is expected to open up new frequency resources.

2 Results of experiment

(1) Experiment on high-speed data transmission using a compact transceiver for terahertz wireless communication

In this experiment, an InP-based high-electron-mobility transistor (InP-HEMT) was used as an ultrahigh-speed device and incorporated in a high-frequency transceiver circuit designed as an integrated circuit (IC). In this manner, a compact transceiver for terahertz wireless communication using the 300-GHz band was created. The transmitter enables 20-Gbps data transmission as an integrated architecture connecting (via a waveguide) a metal package housing the IC and an antenna . Moreover, under the assumption that the receiver will be mounted in a smartphone-sized terminal, mounting the IC in the antenna-integrated metal package resulted in an overall size of 1 cc (previously reported). The receiver demodulates a 20-Gbps wireless signal (received via the wireless section) and outputs it as a data signal. In addition, as for radiowave propagation and measurement technology concerning the 300-GHz band, high-speed data transfer was verified by an experiment performed in an anechoic chamber.

In this verification experiment, the transmitter and a signal processor for forward error correction (FEC) etc. (both developed by NTT), the receiver (developed by Fujitsu), and the radiowave propagation and measurement technology (developed by NICT) were brought together in the configuration. With the developed transmitter and receiver set facing each other, 20-Gbps data transfer was achieved. As a result, as for transmission distances exceeding 1 m, the possibility of error-free transmission was confirmed.

Furthermore, an experiment on polarization-multiplexing transmission using two transceiver sets and a polarized waves perpendicular to each other was performed, and the results of the experiment confirmed that 40-Gbps data transfer is possible. These experiments confirmed sufficient performance as a wireless device transceiver and the utility of the developed technology.

(2) Verification experiment simulating a data-downloading service

With the developed transmitter installed in an information terminal, and the matching developed receiver installed in a smartphone-sized terminal, a verification experiment simulating a service for downloading data (by touching the smartphone-sized terminal on the information terminal) was performed. In this experiment, video files stored in a PC on the transmission side (i.e., a contents server) were used, and the transfer rate concerning those files was evaluated. As a result, high-speed downloading of data at 2 GB/s (gigabytes per second)--equivalent to downloading at a rate of one DVD's worth of data in about three seconds--was confirmed. Under the aim of providing a high-speed downloading service, although investigations on using millimeter waves are presently progressing, the effectiveness of using terahertz wireless communication to further increase data-transfer rate was confirmed in this experiment.

3 Future developments

From now onwards, while further increasing data-transfer rate and improving efficiency of the communication sequence, in anticipation of studies on frequency utilization, we will continue our vigorous investigations on usage cases in addition to contents downloading.
-end-


National Institute of Information and Communications Technology (NICT)

Related Terahertz Waves Articles:

Terahertz waves reveal hidden processes in ultrafast artificial photosynthesis
Osaka University researchers have succeeded in observing charge transfer and intermolecular interactions in ultrafast artificial photosynthesis.
Terahertz technology escapes the cold
The group of Jérôme Faist in the Department of Physics at ETH Zurich achieved the first realization of a terahertz quantum cascade laser operating without cryogenic cooling.
On-demand control of terahertz and infrared waves
A theory from 2006 predicts that it should be possible to use graphene in a magnetic field not only to absorb terahertz and infrared light on demand but also to control the direction of the circular polarisation.
Laser trick produces high-energy terahertz pulses
A team of scientists from DESY and the University of Hamburg has achieved an important milestone in the quest for a new type of compact particle accelerator.
Balancing the beam: Thermomechanical micromachine detects terahertz radiation
Researchers at The University of Tokyo developed a microelectromechanical device that detects terahertz radiation at room temperature.
More Terahertz Waves News and Terahertz Waves Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Erasing The Stigma
Many of us either cope with mental illness or know someone who does. But we still have a hard time talking about it. This hour, TED speakers explore ways to push past — and even erase — the stigma. Guests include musician and comedian Jordan Raskopoulos, neuroscientist and psychiatrist Thomas Insel, psychiatrist Dixon Chibanda, anxiety and depression researcher Olivia Remes, and entrepreneur Sangu Delle.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...