China’s latest anti-stealth metric wave radar is the size of a clothes rack

While the Chinese government has been lauding the development of new quantum radar and quantum “ghost” satellite systems that “make US stealth capabilities obsolete” for some while now, as have others such as Austria, Canada, and the UK, this week Chinese scientists announced they’ve allegedly developed an anti-stealth radar that could be quietly and easily set up almost anywhere, including a rooftop. The news was reported in the South China Morning Post.

Anti-stealth radar systems often need a big antenna to pick up the weak signature of stealth planes that use technology to block or deflect radar signals. This new compact system, however, if true, could prove to be revolutionary.

“Although the detection accuracy of the radar can be improved by increasing the antenna aperture, it will reduce the mobility and survivability of the radar platform,” said professor Yang Minglei in a paper published in the domestic peer-reviewed journal Modern Radar on August 11.

The metric wave radar array is comparable in size and looks like a "clothes-drying rack." It was created by Yang and his colleagues of the national laboratory of radar signal processing at Xidian University, Xi'an, according to a picture published in the journal.

Researchers say that in several tests done on top of a building on a university campus, the mobile device did better in terms of accuracy and range of detection.

China has a complex air defense system that includes anti-stealth radar stations, especially along the South China Sea and eastern Pacific Ocean coasts.

In 2013, Wu Jianqia, lead scientist in the military's anti-stealth radar program, claimed that Chinese radar systems could detect and track American F-22 jets, which are thought to be the most advanced and potent stealth fighters in the world, flying several hundred kilometers off the Chinese coast.

The Chinese anti-stealth radar uses waves with a frequency of just over 3.3 feet (about a meter). According to Wu, these low-frequency waves may contact the massive parts of the stealth aircraft, like its wings or tail, and produce echo signals that are more than 100 times stronger than those of military radar that uses higher frequencies.

As you’d expect, the majority of metric wave radars are enormous. Even portable versions, when fully extended, can reach heights of tens of meters. They typically take hours to set up and require massive trucks to tow them about which makes them prime targets for satellites and drones.

In 2019, the Israeli air force destroyed Syria's Chinese-made JY-27 metric wave radar. Based on the information available to the public, the device was thought to be a smaller version of those used by the People's Liberation Army. But, the incident has made people worry about how long these anti-stealth systems will work.

However, Yang's team's metric-wave radar system is made up of two identical antennas on the same roof, about 20 meters apart.

After one antenna sent out a burst of low-frequency electromagnetic pulses, the two antennas, which were connected by an optical wire, would work together to detect the signals that came back.

Researchers say that the relatively large coverage area of the dual-antenna array made it possible for the device to pick up more long waves reflected off a target.

The distance between the antennas also produced extra noise or erroneous signals that might have harmed accuracy.

Although the concept of splitting a large metric wave antenna into multiple smaller ones has existed since the 1980s, Yang claims that real applications of the technology are still uncommon due to instability and a degree of inaccuracy, but this is solved  using some “clever software.”

The Chinese researchers behind the new radar has also claimed that by analyzing data gathered by antennas in various places, they had built an algorithm that could separate useful information from loud background noise.

Yang's team said that the new radar sent out more data than usual, so they had to use four locally-made Hunxin 1 chips.

The Hunxin 1 is a processor the size of a coin designed and made in China. It was made with 55nm technology, which is too old to be affected by US sanctions against China. It has been widely used in Chinese cars, factories, and military equipment for almost a decade because it is cheap, works well, and stays stable in tough situations.

“The chip has a quad-core parallel processing structure with powerful floating-point computing capabilities, which can very well meet the application requirements of high-speed real-time signal processing,” Yang said.

Because stealth technology is so sensitive, no one knows yet how well the new radar will work to find real stealth aircraft. But Yang's team said that they had been using the system to track many civilian planes, and the data showed that it seemed to be a good solution. And, in other parts of China, researchers are developing other new anti-stealth radar systems too.

For example, a research team from the Nanjing Research Institute of Electronics Technology has claimed that they had created a small metric radar that could open up considerably more quickly than current models. And, elsewhere, other research teams are boosting the power of high-frequency radar in order to increase the range and possibility of detecting stealth targets.

If these claims are true, then beams from many radar stations hundreds of kilometers away can be used to light up a stealth target, and that could pose a problem for any adversaries.