THz FDM yields 50Gbit/s communication
- Author:Ella Cai
- Release on:2017-08-11
International researchers demonstrated THz frequency-division multiplexing with an aggregate data rate of 50Gbit/s.
“We showed that we can transmit separate data streams on terahertz waves at very high speeds and with very low error rates,” said Professor Daniel Mittleman or Browns University in the US. “This is the first time anybody has characterised a terahertz multiplexing system using actual data, and our results show that our approach could be viable in future terahertz wireless networks.”
The mux/demux approach developed uses two parallel metal plates, forming a waveguide (see image, which includes an artists montage). One of the plates has a slit cut into it.
When terahertz waves travel through the waveguide, some of the radiation leaks out of the slit. The angle at which radiation beams escape is dependent upon the frequency of the wave.
“We can put several waves at several different frequencies, each of them carrying a data stream, into the waveguide, and they won’t interfere with each other,” said Mittleman. “Each of those frequencies leaks out of the slit at a different angle, separating the data streams; that’s demultiplexing.”
In 2015, Mittleman’s lab published a paper describing their waveguide concept – initially using a broadband terahertz source to confirm that different frequencies did indeed emerge from the device at different angles.
In the new work, two high-definition television broadcasts were encoded separately onto carriers at 264.7 and 322.5GHz, then modulated together, sent through a link, then demodulated.
Transmissions were “error-free”, said the University, up to 10Gbit/s, and then “increased somewhat when the speed was boosted to 50Gbit/s – 25Gbit/s/channel, but were still well within the range that can be fixed using forward error correction.”
It transpires that the angle of the receiver is important. “If the angle is a little off, we might be detecting the full power of the signal, but we’re receiving one side-band a little better than the other, which increases the error rate.” said Mittleman. “It’s something we didn’t expect, and it shows how important it is to characterise these systems using data rather than just an unmodulated radiation source.”
The work is published in Nature Communications.
Brown University worked with Guillaume Ducournau at Institut d’Electronique de Microélectronique et de Nanotechnologie, CNRS/University of Lille, in France.
The project was supported by the US National Science Foundation, US Army Research Office, WM Keck Foundation and France’s Agence Nationale de la Recherche under the COM’TONIQ and TERALINKS research grants and in the framework of the CPER ‘Photonics for Society’ developed within the Hauts-de-France region.
“We showed that we can transmit separate data streams on terahertz waves at very high speeds and with very low error rates,” said Professor Daniel Mittleman or Browns University in the US. “This is the first time anybody has characterised a terahertz multiplexing system using actual data, and our results show that our approach could be viable in future terahertz wireless networks.”
The mux/demux approach developed uses two parallel metal plates, forming a waveguide (see image, which includes an artists montage). One of the plates has a slit cut into it.
When terahertz waves travel through the waveguide, some of the radiation leaks out of the slit. The angle at which radiation beams escape is dependent upon the frequency of the wave.
“We can put several waves at several different frequencies, each of them carrying a data stream, into the waveguide, and they won’t interfere with each other,” said Mittleman. “Each of those frequencies leaks out of the slit at a different angle, separating the data streams; that’s demultiplexing.”
In 2015, Mittleman’s lab published a paper describing their waveguide concept – initially using a broadband terahertz source to confirm that different frequencies did indeed emerge from the device at different angles.
In the new work, two high-definition television broadcasts were encoded separately onto carriers at 264.7 and 322.5GHz, then modulated together, sent through a link, then demodulated.
Transmissions were “error-free”, said the University, up to 10Gbit/s, and then “increased somewhat when the speed was boosted to 50Gbit/s – 25Gbit/s/channel, but were still well within the range that can be fixed using forward error correction.”
It transpires that the angle of the receiver is important. “If the angle is a little off, we might be detecting the full power of the signal, but we’re receiving one side-band a little better than the other, which increases the error rate.” said Mittleman. “It’s something we didn’t expect, and it shows how important it is to characterise these systems using data rather than just an unmodulated radiation source.”
The work is published in Nature Communications.
Brown University worked with Guillaume Ducournau at Institut d’Electronique de Microélectronique et de Nanotechnologie, CNRS/University of Lille, in France.
The project was supported by the US National Science Foundation, US Army Research Office, WM Keck Foundation and France’s Agence Nationale de la Recherche under the COM’TONIQ and TERALINKS research grants and in the framework of the CPER ‘Photonics for Society’ developed within the Hauts-de-France region.
