Satellite Internet services are rapidly expanding, but the ground terminals required to connect to satellite Internet services are expensive and power-hungry. French startup Greenerwave is building terminals that use what they call “reconfigurable intelligent surfaces” (RIS) to reduce both cost and energy consumption.
Low-Earth Orbit (LEO) satellite constellations from companies like Starlink and Eutelsat OneWeb promise to provide connectivity anywhere in the world. But establishing links with satellites that are constantly on the move and quickly switching between them to maintain a reliable connection requires advanced antenna technology.
Currently, most services rely on phased array antennas. A phased array antenna consists of multiple small antennas that work together to form and direct a radio beam. This makes it possible to lock on to moving targets, but requires complex and expensive electronics that consume large amounts of power. Instead, Paris-based Greenerwave has built a terminal that relies on RIS. RIS consists of a number of small tunable reflection units that work together to change the direction and characteristics of the beam reflected from a surface.
Because the antenna uses very simple electronics, it is more cost-effective than those relying on phased arrays and uses 10 times less energy than traditional systems, CEO Geoffroy Lerosey said. I am. He said RIS technology could not only reduce costs but also enable new applications such as satellite terminals in cars and airplanes. GreenWave plans to start selling the devices by the end of the year, Lilosy said.
He also reported that GreenWave is in talks with Intelsat, a satellite multinational based in Tysons Corner, Virginia, to develop a custom terminal. Contacted for this statement, an Intelsat spokesperson confirmed the memorandum of understanding between the two companies and said, “Greenerwave’s innovative terminal technology fits very well with Intelsat’s multi-orbit strategy. Greenerwave’s low cost, Low power products differentiate our services in the market and help enable a wider range of satellite communications applications.โ
Greenerwave’s RIS satellite internet ground terminal has a large enough footprint and modest energy budget to imagine new applications in cars and drones. greener wave
โWe offer antennas that are more cost-effective and lower cost than our competitors. [power] Itโs consumption,โ says Rilogy. โBut because of the low power consumption, we are also allowing new industries to use this type of technology.โ
Metamaterials achieve better tuned wavefronts
To establish a communications link between a moving satellite and a ground station on Earth, both must be able to steer their radio beams toward each other. One sends data and the other sends data. This is typically done using a phased array antenna, which uses a process called beamforming, where many small antennas transmit signals in different phases. These signals interfere with each other either constructively or destructively, and by carefully controlling this interference pattern, the antenna produces a single radio beam whose shape and direction can be controlled.
In contrast, Greenerwave’s terminals use technology based on research LeRosie conducted at the Langevin Institute in Paris on “metamaterials,” or man-made materials with properties not normally found in nature. At the heart of the company’s device is a 2D metamaterial known as a metasurface that is designed to manipulate electromagnetic waves. It consists of many small reflective elements that can switch between high and low electrical impedance, changing the phase of the reflected waves.
When this surface is shined with a radio beam, the reflective elements generate signals with different phases, similar to small antennas in a phased array. These interfere with each other to produce radio beams whose direction, phase, polarization, and even bandwidth can be precisely controlled. Antennas can also create multiple beams whose characteristics and directions can be individually set.
The key difference between the antenna technologies, Lerosey said, is that each antenna in a phased array requires a dedicated integrated circuit. This increases overall system complexity, cost, and power consumption. By contrast, the electronics in Greenerwave’s devices are relatively modest, he says. “This surface component is a very simple switch,” he says. “It’s just a few transistors. It’s really small. It costs very little money and uses very little energy.”
Most steerable antennas typically use between 500 watts and 1 kilowatt of power, but thanks to the metasurface antenna’s passive beamforming approach, Greenerwave’s terminal uses just 70 watts. lilothy says. This could open up new applications where energy efficiency is important, such as installing satellite terminals on vehicles and drones.
Although the hardware is simple, Lerosey says precise control of RIS requires complex software. He says there is no equation that can directly predict how a particular reflectance pattern will affect the direction and properties of a beam. The company created a digital twin of the device based on a combination of a physical model of the system and an AI model trained on real-world operational data. This digital twin is used to calculate how to reconfigure the reflectance pattern to achieve the desired beam.
Bill Ray, distinguished vice president analyst at Gartner, says metamaterials have great potential to reduce the cost of satellite communications. That could expand the use of satellite connectivity, he said, and potentially allow devices to be embedded in the roofs of every car, for example. โConsistent production quality is questionable,โ he says. “But now that academic experiments have shown its potential, I wouldn’t be surprised if commercial companies move quickly to take advantage of this technology.”
Greenerwave announced in February that it had raised โฌ15 million to develop its first mass-produced device, which Lerosey said would be available by the end of the year.
Lerosey says their ambitions go beyond satellite communications and the company is currently developing terminals that can be used in 5G networks. The reduced energy consumption of their technology could be attractive to network providers, but he expects it will take some time for the technology to become standard, he says.
Updated May 3, 2024: This article has been updated to include confirmations and statements from Intelsat officials regarding the agreement with Greenerwave.
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