Scientists have developed a groundbreaking surface that performs calculations using light itself, marking a significant leap in electromagnetic wave processing. This innovation, led by researchers at Southeast University in China, opens up new possibilities for signal processing and computation. The key lies in a metasurface, a thin, programmable surface covered in tiny structures that manipulate electromagnetic waves. This metasurface can be electronically reprogrammed, allowing for dynamic control over the direction, phase, and amplitude of incoming radio waves. The researchers chose Fourier transforms and convolutions as the fundamental mathematical operations for this metasurface. These operations enable the surface to break down patterns and find known patterns within signals, making it highly versatile for various applications. By programming the metasurface with specific time-coding sequences, the researchers demonstrated its ability to perform both Fourier transforms and convolutions in real-time. This means the calculations are directly performed on the radio waves as they interact with the metasurface, eliminating the need for digital conversion and processing. The metasurface's versatility is evident in its successful testing in different environments, including a clean lab and outdoor settings with realistic multipath and clutter conditions. It accurately measured velocity and distance, showcasing its potential for radar applications. The system's ability to switch between Fourier transforms and convolutions without hardware modification is particularly impressive. This innovation could lead to simpler radio-frequency signal processing, reducing the reliance on high-speed analog-to-digital converters and digital processors. However, the next challenge is to increase the modulation speed while maintaining accuracy, stability, and energy efficiency. The researchers envision a future where this metasurface technology is applied to radar, 6G communications, satellite systems, and automotive radar, revolutionizing how we process and utilize electromagnetic waves.
