Apr 1 2020
Scientists tested the transmission of very high-frequency signals of 200 GHz via a pair of copper wires. They achieved this by using the same technology that enables high-frequency signals to move on common phone lines.
A 13- by 13-millimeter measurement for each of the 169 possible locations of the signal input location of the waveguide. These measurements reveal multiple maxima in each 13 × 13 spot, confirming a superposition of modes in the signal propagating through the waveguide. Image Credit: Image courtesy of the authors.
The outcome is a link that can transfer data at the rates of terabits per second, which is considerably faster compared to the existing channels.
The technology to disentangle several, parallel signals traveling through a channel is already there. However, questions related to the effectiveness of applying these concepts at higher frequencies have remained due to the signal processing techniques developed by John Cioffi, the inventor of digital subscriber lines (DSL).
Researchers of the study published recently in Applied Physics Letters, from AIP Publishing, tested data transmission at higher frequencies by using mathematical modeling and experimental measurements to characterize the input and output signals in a waveguide.
The team made use of a device with two wires running parallel within a sheath with a large diameter that enables increased mixing of the waveguide modes. Such mixtures allow the transmission of parallel non-interfering data channels. Higher frequencies enable more data and larger bandwidth to travel via a channel if the channel is built such that the data is not distorted by interference.
To confirm and characterize this behavior, we measured the spatial distribution of energy at the output of the waveguide by mapping the waveguide’s output port, showing where the energy is located.
Daniel M. Mittleman, Study Author, Brown University
A 13- by 13-millimeter grid was developed for the output of each possible input condition, which led to a 169 x 169 channel matrix that offers a total characterization of the waveguide channel. The outcomes show a superposition of waveguide modes in the channel and enable the data rates to be estimated.
It is exciting to show that a waveguide can support a data rate of 10 terabits per second, even if only over a short range. That’s well beyond what anybody has previously envisioned. Our work demonstrates the feasibility of this approach to high-rate data transmission, which can be further exploited when the sources and detectors reach the appropriate level of maturity.
Daniel M. Mittleman, Study Author, Brown University
As a next step, the team plans to examine ohmic losses, which is a function of the resistance of each cell component and brought about by the metal hardware of the waveguide, thereby governing the channel’s length. The study can be applied to applications that need huge amounts of data to be transmitted quickly over short distances, for example, for chip-to-chip communication or between racks in a data center.