Chinese scientists develop breakthrough radar to detect stealth fighter jets

In an article published by South Morning Chia Post, Chinese scientists are making significant strides in radar technology that could revolutionize the detection of stealth aircraft, including advanced F-22 fighter jets. 

This innovative radar, which relies on a simple receiving antenna, is both cost-effective and easily deployable anywhere on the planet, while remaining discreet by not emitting detectable signals. In the event of BeiDou interference, the radar can seamlessly switch to other frequency bands, including GPS, Europe’s Galileo, or Russia’s GLONASS, ensuring continuous functionality. A recent peer-reviewed paper published in the Journal of National University of Defence Technology featured an image of an F-22 Raptor to demonstrate the radar’s potential targeting capabilities, suggesting it could also be effective in detecting other stealth aircraft, like the F-35.

While China currently employs advanced anti-stealth radars along its coastlines and on naval vessels, these systems are complex and accessible only to a few powerful nations. In contrast, Western stealth jets often operate undetected in smaller countries like Yemen, Syria, and Lebanon. The BeiDou radar could democratize anti-stealth technology, according to Wen Yuanyuan, a senior engineer at the National Key Laboratory of Space Microwave Communication in Xi’an, Shaanxi province. BeiDou's global navigation system boasts nearly double the number of satellites compared to GPS. When BeiDou signals encounter stealth aircraft, they are refracted, producing unique echoes that researchers can analyze to accurately identify the target and its location. 

According to Wen and her team, the navigation satellite signals offer "strength in all weather, global coverage, continuity, stable transmission frequency, and precise timing," making them ideal for illuminating small and weak radar targets. However, the signals that bounce back from stealth aircraft are weak, and they may also be affected by interference from buildings, trees, and other objects. Until now, it has been widely believed that passive radars require a specialized array of antennas aimed directly at a satellite to capture a clear navigation signal. 

By comparing this reference signal with data from another set of antennas, information about stealth aircraft can be derived. However, this method complicates the signal processing and increases the computational demands. Wen's team instead introduced an innovative "blind detection" method that uses a single channel to identify stealth aircraft without the need for a reference antenna. This design not only reduces the radar's cost but also simplifies its structure, making it easier to deploy and more resilient against enemy interference during conflicts. This advancement was made possible by a unique algorithm developed by Goran Zivanovic in 1991. At that time, the world was adjusting to the aftermath of the Cold War. 

Zivanovic created a method for detecting hidden cyclic frequencies in electromagnetic signals. However, following the publication of his algorithm, he disappeared from academia, and with the dissolution of Yugoslavia a year later, his work went largely unnoticed, receiving little attention from Western scholars over the past 15 years. 

In China, however, Zivanovic's concept has been highly regarded and widely utilized in radar, communication, and sonar technologies. Wen’s team has adapted the original algorithm for detecting stealth target signals, and in simulation tests, it successfully identified the distance, direction, and speed of three stealth targets amid radio noise. China is leveraging various technological advancements to enhance its military capabilities against the US military. 

In addition to navigation satellites, Chinese scientists are exploring other detection methods, including long-wave signals reflected by the ionosphere, radiation from Starlink satellites, and electromagnetic waves emitted by US military base radars. Some Chinese commercial satellites, equipped with artificial intelligence, have also successfully tracked F-22 fighter jets flying through cloud cover. In response to China's rapid advancements in military technology, the US is adjusting its Asia-Pacific strategy. 

In June, the US military announced the transfer of about 10,000 troops from bases in Japan to Guam and Hawaii, which are farther from China. Additionally, some senior Pentagon officials are increasingly favouring the use of drones over traditional combat aircraft in potential military engagements with China.

By Naila Huseynova