Terahertz radiation (T-Ray), also known as submillimeter radiation, could be the next wireless radio band to be used for data, after we move on from 5G.
5G is our next-generation mobile wireless—likely made up of predominantly millimeter spectrum. I've written about 5G recently in "Next-generation 5G speeds will be 10 to 20 Gbps."
T-Ray
T-Ray is a step up the electromagnetic spectrum, just above microwave and short of infrared light waves. Conventional radios can't produce it—hence the need to find solutions.
Data rates could be high, possibly up to 100Gbps.
Terahertz radiation
Bandwidth-plentiful T-Ray, or submillimeter spectrum, as it's also sometimes called, will be fast—up to 100-times faster than today's networks, according to scientists.
It will also be plentiful—a good thing, because we'll eventually use up newly tamed 5G spectrum just like we're getting close to in some places with 4G.
Terahertz issues
The only problem, though, is that T-Ray is uncharted territory. While researchers from the Tokyo Institute of Technology have obtained some lab success, thus far multiplexling and demultiplexing hasn't been addressed.
Multiplexing and demultiplexing are important because they allow multiple streams of data to be sent down one pipe. You need to share the bandwidth.
Multiplexing
Researchers at Brown University say that they have now discovered a way to perform both multiplexing and demultiplexing. Their approach is to use a leaky-wave antenna.
Leaky-wave antennas, which have been around since the 1940s, propagate along the entire length of the antenna.
Two plates
In this case, the antenna is constructed from two metal plates, in parallel, that form a waveguide. One plate has a small slit in it.
"As terahertz waves travel down the waveguide, some of the radiation leaks out of the slit. It turns out that terahertz waves leak out at different angles depending on their frequency," an article on Brown's website reads.
Differing angles
"That means if you put in 10 different frequencies between the plates, each of them potentially carrying a unique data stream, they'll come out at 10 different angles," Daniel Mittleman, professor of engineering at the university, said in the Brown article.
"Now you've separated them and that's demultiplexing," he says.
At the receiving end an antenna accepts the rays at a particular angle.
Adjusting for bandwidth
Adjusting the distance between the plates adjusts the bandwidth that's allocated to each channel.
Mittleman reckons that this could be especially useful if you wanted to allocate bandwidth on the fly. In other words, this kind of antenna could make the spectrum highly flexible.
"If one user suddenly needs a ton of bandwidth, you can take it from others on the network, who don't need as much, just by changing the plate spacing at the right location," he says.
5G
We'll probably be using the latest radio tech known as 5G, and its millimeter spectrum, by 2020.
As we are hearing, some scientists are already working on data via the next chunk of spectrum.