Absorbing layers have been fundamental to advancements in technologies like energy harvesting, stealth systems, and communication networks. Credit: Syracuse University
Electromagnetic absorbers are essential in energy, stealth, and communication technologies, yet current designs underperform. A research team has introduced ultra-thin absorbers nearing theoretical efficiency limits, promising transformative industrial applications.
Absorbing layers are essential to advancements in technologies like energy harvesting, stealth systems, and communication networks. These layers efficiently capture electromagnetic waves across wide frequency ranges, enabling the creation of sustainable, self-powered devices such as remote sensors and Internet of Things (IoT) systems. In stealth technology, absorbing layers reduce radar visibility, enhancing the performance of aircraft and naval systems. They also play a vital role in communication networks by minimizing stray signals and mitigating electromagnetic interference, making them indispensable in today’s interconnected world.
The demand for ultra-thin absorbing layers with broader bandwidths and greater functionality has grown as technology advances. These layers must deliver higher performance while maintaining compact designs. However, a theoretical upper limit exists on the bandwidth-to-thickness ratio for metal-backed, passive, linear, and time-invariant absorbing layers. Current absorbers, regardless of their frequency range or material thickness, fall significantly short of this limit, leaving much of the potential in passive and linear systems untapped.
In a new research paper published on January 21 in Nature Communications, Electrical Engineering and Computer Science Professor Younes Ra’di and his research team introduced a new concept for designing ultra-thin absorbers that enables absorbing layers with a record-high bandwidth-to-thickness ratio, potentially several times greater than that of absorbers designed using conventional approaches. Absorbers designed based on this concept can achieve a bandwidth-to-thickness ratio arbitrarily close to the ultimate bound. Utilizing this concept, they designed and experimentally verified an absorber yielding a very high bandwidth-to-thickness ratio.
“Our findings have the potential to make significant contributions to various industries, including defense, energy harvesting, and advanced communication systems, by addressing critical challenges in electromagnetic absorption technology,” says Ra’di.
“It’s incredibly rewarding to see our work attracting international recognition, not only from the scientific community but also from key players across various industries. I am immensely proud of my team for their dedication and hard work, which have led to these groundbreaking results. Publishing in a prestigious journal like Nature Communications is a testament to their exceptional efforts and the importance of our research.”
Reference: “Passive highly dispersive matching network enabling broadband electromagnetic absorption” by Pardha S. Nayani, Morteza Moradi, Pooria Salami and Younes Ra’di, 21 January 2025, Nature Communications.
