China testing stealth enhancing metamaterial on non-stealth planes

New mass produced metamaterial was developed by a research team at the State Key Laboratory of Millimetre Waves in Southeast University in Nanjing, Jiangsu province. It was being tested on aircraft at a major military aircraft production base in Shenyang, Liaoning province, a researcher in the laboratory confirmed.

Shenyang Aircraft Corporation, a subsidiary of the Aviation Industry Corporation of China, builds non-stealth fighter jets, including the J-11 and the J-15.

Other countries, especially the United States, have also been heavily engaged in the research and development of similar technology to cloak military jets, but there have so far been no public reports on the mass application of such metamaterials overseas.

In 2011, the team said it had developed a radio wave-absorbing device that could make a target invisible to the three most common radio bandwidths used by military radars.

Two years later, the team said it had created a “ghost illusion device” that could allow a plane to leave almost no radar signature. The device could make parts of the plane appear on radar as plastic, instead of metal, or show three planes instead of one, according to the team.

China has about 20 J-20 stealth fighters and roughly 1,500 other kinds of combat aircraft in service, according to some overseas estimates. Upgrading the existing non-stealth aircraft with new metamaterial could greatly improve their combat strength.

Han Yiping, director of applied physics at Xidian University, formerly a military engineering institute, said metamaterials alone could not hide an aircraft from radar.

Stealth aircraft relied on a range of tactics, including low-reflection aerodynamic design and cloaks of ionised particles, to fly undetected.

Metamaterials were also extremely difficult to mass produce, and the technology would have to withstand the heat and shock of battle, meaning some performance would have to be sacrificed for reliability.

Currently the technology was effective within only certain radio bandwidths.

Early this year, Shenzhen-based technology company Kuang-Chi said it had started mass production of a thin, metallic membrane that it claimed was a metamaterial.

In 2013, Boeing began evaluating how to attract future sales from the Navy as production slowed, it started promoting an “Advanced Super Hornet” configuration that would have improved the aircraft’s signature by 50 percent. That version of the jet included structural enhancements and an enclosed weapons pod, but Boeing ultimately stepped away from that concept. Currently there is an updated block III F-18.

Super Hornet’s Block III upgrades slated to be incorporated on jets rolling off the production line in 2020: the application of radar absorbent materials or RAM, also known as stealth coating. Block III jets will get “a little more” of that coating applied to them, “and in a few different areas to buy a little bit more performance,” Gillian told Defense News in a March interview. All in all, those improvements will reduce the aircraft’s radar cross section by about 10 percent, and with very low risk