China powers up new radar tech to unmask stealth fighters

Chinese arms firm tests T-ray system designed to penetrate anti-detection coatings on aircraft

http://www.scmp.com/news/china/society/article/2113113/china-powers-new-radar-tech-unmask-stealth-fighters

China North Industries Group Corporation tested a device capable of generating terahertz radiation with unprecedented power at a military research facility in Chengdu, Sichuan province, last week, Science and Technology Daily reported on Monday.

Terahertz radiation, or T-rays, can penetrate composite materials to reach underlying metallic layers and is widely used in industrial plants to spot product defects.

Terahertz radars are already capable of finding a concealed weapon in a crowd from hundreds of metres away, and a more powerful version is under development to put on an early warning aircraft or satellite to identify and track military aircraft, including the US’ F-22 and F-35 stealth fighters.

Attempts to realise military applications for T-ray technology have been limited by the bulk and low power output of terahertz generators. The rays fall on the spectrum between microwaves and light and cannot be produced by conventional radio or optical devices.

The report said the new device could generate stable, continuous radiation at an average level up to 18 watts, and terahertz pulses with peak power close to one megawatt, on par with some military radars.

A technical executive at a vendor in China for T-ray devices used in F-35 manufacturing said the reported power levels of the device were “more than a million times higher than the power of the T-ray device used to measure the thickness of coatings on the F-35”.

“The radar-absorbent coatings on the F-35 will look as thin and transparent as stockings if [the Chinese instrument] is as powerful as they claim,” the executive said.

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“It looks like they will soon be able to have an echo image of the F-35 with some high-definition details ... from a respectable distance.”

China has claimed that some of its existing very-high-frequency military radar can detect traces of stealth aircraft but doubters say the microwaves from those devices would be absorbed or deflected by stealth materials.

Qi Jiaran, deputy director of the department of microwave engineering at the Harbin Institute of Technology, said the new instrument could be a game changer.

Qi, a terahertz imaging specialist not directly involved in the Chengdu project, said the report suggested that China had made a breakthrough in some key technology and components.

But the technology was still bulky and could not be fitted easily on a plane or satellite.

“Field deployment may require power output at the kilowatt level. There is still a long way to go before we can monitor stealth fighters or bombers from space,” Qi said.

The new instrument was developed by the China Academy of Engineering Physics in Mianyang, the nation’s largest research institute for the development and production of nuclear weapons.

According to the academy’s website, efforts were under way to increase the device’s power output and shrink its size for military applications.