A new study has developed a method to bend terahertz signals around obstacles, which could greatly impact wireless communication. With current cellular networks and Wi-Fi systems close to their bandwidth limits, scientists are looking for higher communication frequencies for the future. However, there are literal obstacles that need to be addressed before this transition can happen. Brown University and Rice University researchers have made progress in this area.In a recent study published in Communications Engineering, researchers have discovered a way to use light to overcome obstacles such as walls, furniture, and even people. This is a significant breakthrough in wireless communication, as current systems rely on microwave radiation to transmit data. However, it has become evident that the future standard for data transmission will involve terahertz waves, which can carry up to 100 times more data than microwaves. One challenge with terahertz signals is that they can be blocked by most solid objects, unlike microwaves. This discovery is a step towards addressing this issue.The transmission of high-frequency signals will require a direct line of sight between the transmitter and receiver, which is a crucial factor to consider. According to Daniel Mittleman, a professor at Brown’s School of Engineering and the senior author of the study, most people currently use a Wi-Fi base station that emits wireless signals throughout a room. However, at higher frequencies, the signal will be more directional, requiring the beam to follow the user as they move in order to maintain the link. If the user moves outside of the beam or if something obstructs the link, the connection will be disrupted.
“If you’re behind a wall, then you’re not getting any signal.”
The researchers found a way around this by creating a terahertz signal that goes around an obstacle instead of being blocked by it. This new method could change the way we communicate wirelessly and shows the potential for wireless data networks using terahertz frequencies, according to the researchers.
“We want to transfer more data per second,” Mittleman explained. “To do that, we need more bandwidth, and that bandwidth simply isn’t available using traditional frequency bands.”
In their study, Mittleman and his team introduced a new way to transmit signals using terahertz frequencies.The researchers have introduced the concept of self-accelerating beams, which are unique configurations of electromagnetic waves that naturally bend or curve to one side as they travel through space. While these beams have previously been studied at optical frequencies, they are now being investigated for terahertz communication.
Building on this concept, the researchers developed transmitters with carefully crafted patterns to enable the manipulation of the strength, intensity, and timing of the electromagnetic waves they produce. This manipulation allows the waves to work together more effectively.The light beam adjusts to blockages by shuffling data along the patterns engineered into the transmitter, maintaining the signal when a solid object blocks a portion of the beam. When one pattern is blocked, the data transfers to the next one, ensuring the signal link remains intact. This level of control allows the signal to bend around objects as long as the transmitter is not completely blocked. If the transmitter is completely blocked, another method of generating the signal is necessary.
It will be necessary to send the data to the receiver.
Hichem Guerboukha, who led the study as a postdoctoral researcher at Brown University and is now an assistant professor at the University of Missouri — Kansas City, stated, “Curving a beam doesn’t solve all possible blockage problems, but what it does is solve some of them and it solves them in a way that’s better than what others have tried.”
The researchers confirmed their findings through extensive simulations and experiments to maintain communication links with high reliability and integrity while navigating around obstacles. This work is a continuation of a previous study from the team that demonstrated terahertz.The researchers are exploring the possibility of bouncing data links off walls within a room, with minimal loss of data. Their goal is to use curved beams to improve the reliability of wireless networks, particularly in crowded or obstructed environments. This advancement could result in faster and more stable internet connections in places like offices or cities where obstacles are common. However, there is still a lot of fundamental research and challenges to address as terahertz communication technology is still in its early stages. According to Mittleman, one of the key questions they face is the extent to which they can curve the beams and how far they can reach.”We have made approximate calculations for these phenomena, but we have not yet accurately measured them, so we aim to graph them out.”
Journal Reference:
- Hichem Guerboukha, Bin Zhao, Zhaoji Fang, Edward Knightly, Daniel M. Mittleman. Curving THz wireless data links around obstacles. Communications Engineering, 2024; 3 (1) DOI: 10.1038/s44172-024-00206-3