New research, by Brown University, has brought us one step closer to terahertz wireless communication that could deliver data hundred times faster than the Wi-Fi and cellular networks of present times. For the very first time, scientists have successfully developed an integral component of terahertz-based data transfer: the technology for multiplexing different waves, so that they can travel through a single medium.
Today’s Wi-Fi and cellular networks use microwaves to transmit data, like voice and video calls. Such systems, however, will soon be unable to handle the rapidly-increasing demands for high-speed data transfer. By contrast, terahertz radiation, also called submillimeter radiation, contains electromagnetic waves with very high frequency and consequently, higher potential bandwidth. Unfortunately, the scientific world has only recently begun studying the different properties and potential uses of terahertz waves.
The new research, published in the Nature Photonics journal, marks the first time that scientists have been able to develop a multiplexer for terahertz wireless networks. A multiplexer, also known as mux, is a device that allows separate streams of data to flow through a particular medium without overlapping. It is this process of multiplexing that enables a single cable line to carry several TV channels or a fiber optic cable to transport multiple phone calls and emails, simultaneously. Speaking about the project, Daniel Mittleman, an engineering professor at Brown and the study’s senior author, said:
Any terahertz communications application is going to need some form of multiplexing and demultiplexing. This is, to our knowledge, the first time anyone has demonstrated a viable strategy for multiplexing in the terahertz range.
The technology, developed by the researchers, is based on what is known as leaky wave antenna. It refers to a type of waveguide, built using two parallel plates of metal. One of the plates contains a tiny slit, through which the terahertz radiation seeps out at different angles, according to their frequency. A receiver, placed at the other end of the setup, could be programmed to accept waves at a specific angle, thereby acquiring data from a single stream. Mittleman explained:
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. Now you’ve separated them and that’s demultiplexing.
What is more, altering the distance between the metal plates actually allows the scientists to adjust the spectrum bandwidth assigned to every channel. The research group is currently working with Japan’s Osaka University to check the performance of the device in a prototype terahertz network. Although the breakthrough is a major step towards developing terahertz-based wireless communication systems, a lot of work still needs to be done before it is ready for real-life implementation. The team added:
This is a first-generation, proof-of-concept device. There are still things we can do to improve it and we’ll continue to study it… The biggest impact this may have is it may just be the kick that people need to start thinking about this issue. That means they’ll start coming up with clever ideas that are entirely different from this one