It won’t be long before 5G makes 4G LTE a thing of the past. Always thinking outside the box, researchers have developed a rectenna capable of harvesting energy from 5G signals to power IoT devices.
Corporations, big tech and governments around the world are working hard to find renewable energy sources to power technology. Current methods and processes within the technology sector consume massive amounts of energy. Even though there is a chip shortage, the chips available today can handle hundreds of watts more energy than previous designs. Recently we discussed a wearable microgrid that harvests unused energy from human movement, like swinging your arms. Last month in a press release, researchers at the Georgia Institute of Technology announced an, “innovative way to tap into the over-capacity of 5G networks,” with the development of the ‘Rectenna’.
What does that mean, though, to “tap into the over-capacity of 5G networks”? Essentially, the researchers discovered a way to turn 5G networks into “a wireless power grid” for powering IoT devices. It could potentially replace the batteries we use in our electronic devices, meaning we could vastly reduce our electricity use since plugging in a device will be needed less, if at all. The rectenna, which we’ll dive into momentarily, could even lessen our need for batteries at all. This is great for the environment because it means less mining for lithium ion batteries, and less impact on the ecosystem at the end of its lifecycle. Lithium ion batteries are known to leak fluid when no longer in use, fluid which contains harmful toxins.
So how does this work exactly? What is a “rectenna” and how does it work? A rectenna is a flexible Rotman lens-based rectifying antenna. Shortening it to rectenna seems apt since that is a mouthful. The Georgia Tech innovation is the first system that can perform millimeter-wave harvesting in the 28-GHz band.
Tapping into 5G as a source of energy is not a new concept, but prior to this researchers struggled to figure out the best way to do it. Large antennas were needed to harvest enough power to supply devices. Two problems happened here: 1. Large antennas have a narrowing field of view, and 2. The antenna’s needed to have a direct line of sight to the 5G base.
From the press release, “Operating just like an optical lens, the Rotman lens provides six fields of view simultaneously in a pattern shaped like a spider. Tuning the shape of the lens results in a structure with one angle of curvature on the beam-port side and another on the antenna side. This enables the structure to map a set of selected radiation directions to an associated set of beam-ports. The lens is then used as an intermediate component between the receiving antennas and the rectifiers for 5G energy harvesting.”
The rectenna system achieved a 21-fold increase in harvested power when compared with a referenced counterpart in demonstrations, and was also able to maintain identical angular coverage. Researchers developed playing card-sized mm-wave harvesters on a variety of layers, both flexible and rigid, using 3D printers.
Jimmy Hester, a senior lab advisor and the CTO and co-founder of Atheraxon (a Georgia Tech spinoff that develops 5G RFID technology) said, “I’ve been working on energy harvesting conventionally for at least six years, and for most of this time it didn’t seem like there was a key to make energy harvesting work in the real world, because of FCC limits on power emission and focalization. With the advent of 5G networks, this could actually work and we’ve demonstrated it. That’s extremely exciting — we could get rid of batteries.”
Not many people have envisioned a world without batteries, even after learning of this innovation, it seems far-fetched to think we’ll ever see a world without batteries. Imagine how much lighter devices will become, how much thinner and smaller. We won’t ever have to worry about a device dying because it hasn’t been plugged or its battery died.
There is a major push to make technology more energy efficient, to reduce the amount of energy it takes to provide compute power, to reduce emissions by data centers. This isn’t going to fix those problems, but it is a step in the right direction. Someone will find a way to use that harvesting power in another way that will help solve a different problem. The more ways we can use these innovations to supply our energy, the closer we are to restricting use of our natural resources. Keeping this planet safe and healthy for future generations is imperative.