In a breakthrough that could revolutionize wireless communications, researchers have uncovered a new method of directing terahertz waves that allows them to bend around obstacles rather than being blocked by them.

Although cellular networks and Wi-Fi systems are more advanced than ever, they are also rapidly reaching bandwidth limits. Scientists know they will soon have to switch to much higher communication frequencies than current systems use, but there are a number of — literally — hurdles ahead before that happens.

Researchers at Brown University and Rice University say they’re one step closer to penetrating solid obstacles like walls, furniture and even people, and they’re doing it by bending light.

Advances in terahertz communications

In a new study published Communication EngineeringResearchers describe how they helped solve one of the biggest challenges facing wireless communications. Current systems rely on microwave radiation to transmit data, but it has become clear that the future data transmission standard will use terahertz waves with a bandwidth 100 times that of microwaves. One long-standing problem is that, unlike microwaves, terahertz signals can be blocked by most solid objects, making direct line of sight between transmitter and receiver a logistical necessity.

“Most people probably use a Wi-Fi base station that floods the room with wireless signals,” said Daniel Mittleman, a professor at the Brown School of Engineering and senior author of the study. “They stay in communication no matter where they go. At the higher frequencies we’re talking about here, you won’t be able to do that anymore. Instead, it will be a directional beam. If you move, the beam will have to follow you to maintain communication, and if you move outside the beam or something blocks the communication, you won’t get any signal at all.” “

The researchers solved this problem by creating a terahertz signal that follows a curved path around the obstacle, rather than being blocked by it.

“This is the world’s first curved data channel and a major milestone in realizing 6G’s vision of high data speeds and high reliability,” said Edward Knightley, co-author of the study and professor of electrical and computer engineering at Rice University.

According to the researchers, the new method presented in the study could help revolutionize wireless communications and highlight the possibility of wireless data transmission networks operating at terahertz frequencies in the future.

“We want more data per second,” Mittleman said. “If you want to do this, you need more bandwidth, and that bandwidth is not available using traditional frequency bands.”

New methods of signal transmission

In the work, Mittleman and colleagues introduce the concept of self-accelerating beams. Rays are special configurations of electromagnetic waves that naturally bend or twist to one side as they move through space. The beams have been studied at optical frequencies, but are now being studied for terahertz communication.

Researchers used this idea as a starting point. They developed transmitters with carefully designed patterns so that the system could vary the strength, intensity and timing of the electromagnetic waves produced. With the ability to manipulate light, researchers can make the waves work together more efficiently to preserve the signal when a solid object blocks part of the beam. Essentially, the light beam adapts to jamming data into the transmitter in patterns designed by the researchers. When a model is locked, data is transferred to the next, and if locked, to the next. This keeps the signal connection completely intact. Without this level of control, the system cannot make any adjustments when the beam is blocked, so the signal cannot be transmitted.

This effectively causes the signal to bend around objects unless the transmitter is completely blocked. If it is completely blocked, another method will be required to transfer data to the recipient.

“Beam bending does not solve all possible blocking problems, but it solves some, and it solves them better than others have attempted,” said Gichem Gerbuha, who led the research as a postdoctoral researcher. at Brown and is currently an associate professor at the University of Missouri-Kansas City.

The researchers validated their findings through large-scale simulations and experiments, overcoming obstacles to maintain communication links with high reliability and integrity. The work builds on the team’s previous research showing that terahertz-band data channels can bounce off walls in a room without losing much data.

Practical applications and current research

By using these curved beams, researchers hope to one day make wireless networks more reliable even in crowded or indoor environments. This can result in a faster and more stable Internet connection in places where interference is common, such as an office or city. But there is still a lot of fundamental research to be done and many challenges to be overcome before we can get to this point because terahertz communication technology is still in its infancy.

“One of the big questions everyone asks us is how much you can bend and how far you can go,” Mittleman said. “We’ve made a rough estimate of these, but we haven’t quantified them yet, so we’re hoping to map them.”