China says low-cost tech can detect US stealth fighters with pinpoint accuracy

LPIR is designed to avoid detection by radar systems by emitting very weak signals, using frequency hopping and noise-like waveforms, and using adaptive power control and advanced signal processing.

To this end, it differs from traditional radar systems, which broadcast strong, focused signals easily detected from far away. LPIRs, on the other hand, enable similar functions while staying hidden and avoiding alerting enemy systems that they are being scanned. 

Defeating stealth on a budget

You can liken this to whispering across a crowded room using a secret language, randomly changing times and tones while everyone else shouts. You can hear other people clearly, but they can’t realize you’re talking.

This stealthy radar signature, in theory, allows US platforms to detect others without being detected themselves, which is obviously a huge tactical advantage. While LPIR is very hard to detect, it is essential to note that it is not impossible with existing technology.

For example, high-resolution, wideband receivers, advanced signal analysis algorithms, longer observation time for correlation and triangulation, and artificial intelligence (AI) tools can detect it.

To get around LPIR, the Chinese researchers at the 38th Research Institute of China Electronics Technology Group Corporation have reportedly used 500,000 yuan (US$68,600) spectrum analyzers (typically used in telecoms work) to detect these emissions.

The device also claims to locate the source within 0.4-0.5 inches (10-13.5mm), even if jamming is active. One such device, the TFN RMT744A, is commercially classified as civilian telecom equipment but behaves like a military-grade sensor in its field tests.

According to reports, no further technical information has been publicly released, but it is postulated that the device could use advanced signal processing and machine learning. It likely also benefits from precise calibration, hardware tuning, and sophisticated means to counteract LPIR’s anti-detection tricks (like rapid frequency hopping).

Levelling the playing field

If claims about the new device are valid, then this would dramatically reduce the advantage of U.S. stealth technology. If an adversary can detect the radar, they can track or target stealth assets.

It would also level the playing field regarding electronic warfare (EW), especially in a high-tech conflict (e.g., the South China Sea or the Taiwan Strait). Moreover, this new device demonstrates how cheap commercial tech (civilian gear) can be repurposed for military use, making electronic countermeasures more accessible.

This new technology also raises significant questions about the future of nations’ stealth strategies, especially the US. As detection capabilities become cheaper and more sophisticated, the cost-benefit balance of stealth systems may shift.

Nations relying heavily on radar stealth could be forced to rethink doctrines, invest in new countermeasures, or adopt alternative survival approaches.