Using radio systems for communications in a hostile environment has always involved a technical risk: issue energy means leaving a trace . For decades, the challenge has been to find a system that allows information transmission without detection. Recently, researchers in China may have made a significant breakthrough in this area.
According to SCMP, scientists have developed a novel solution that deviates from traditional models: it allows data to be sent without emitting active signals. There are no radio pulses, nor are microwaves used. The system leverages existing radar satellites—like the Gaofen-3 and Ludi Tance 1—to utilize their own echoes as a medium for transporting information.
It is Not What is Issued, but What is Reflected
The key lies in an intelligent surface composed of hundreds of programmable metamaterial tiles . When a synthetic aperture radar (SAR) illuminates a target—such as a tank, ship, or airplane—these tiles manipulate the reflected signal by altering its phase: 0° when “on” and 180° when “off.” This simple alteration allows messages to be encoded directly within the radar echo.
This system modulates what it receives, all without obstructing radar functionality. Researchers assert they have managed to maintain image fidelity with a loss of less than 10%. Platforms using this technology could effectively exchange information without revealing their positions and thus operate stealthily.
<span>Smart surface formed by programmable metamaterial tiles</span>However, making this type of communication effective goes beyond merely playing with reflections. The main challenge was to thrive in environments saturated with signals, where electromagnetic noise can distort everything, and in chaotic seas, where constant balancing can affect reflected signals. The team, led by Liu Kaiyu , has developed algorithms capable of boosting the signal-to-noise ratio by up to 300%, as well as inertial sensors that continuously correct the movement of the platforms in real time.
<span>Metasuperficie of information combined with a passive wireless communication system</span>To date, this technology has only been tested in controlled environments, including laboratories, simulations, and data analysis obtained via satellite. There is currently no evidence of its deployment in actual battlefield conditions. However, Liu’s team has ambitious plans to implement real-world testing with actual platforms to validate the system’s resilience against signal disruption.
<img alt="China's military ambition has no limits. It has just resurrected one of the great Soviet fantasies: the EkranoPlano " width="375" height="142" src="https://i.blogs.es/838e5b/ps---plantilla-portadas-xtk-436/375_142.jpeg"/>The future roadmap includes integrating this technology with various radar systems and creating a network that connects space, air, and ground operations. The ultimate goal is to build a secure communications framework capable of functioning even in scenarios of intense electronic warfare . For those interested, details of the investigation are available in a published article in the Journal of Radars.
Images | Liu Kaiyu and Team | Xataka with Grok | ABODI VESAKARAN
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