The researchers developed a new material they say can defeat microwave radar at ultrahigh frequencies, or UHF. Such material is usually too thick to be applied to aircraft like fighter jets, but this new material is thin enough for military aircraft, ships, and other equipment.
Today’s synthetic aperture radar use arrays of antennas directing microwave energy to essentially see through clouds and fog and provide an approximate sense of the object’s size, the so-called radar cross section. With radar absorbent material not all of the signal bounces back to the receiver. A plane can look like a bird.
“Our proposed absorber is almost ten times thinner than conventional ones,” said Wenhua Xu, one of the team members from China’s Huazhong University of Science and Technology, in a statement.
In their paper, published today in the Journal of Applied Physics, the team describes a material composed of semi-conducting diodes (varactors) and capacitors that have been soldered onto a printed circuit board. That layer is sitting under a layer of copper resistors and capacitors just .04 mm thick, which they called an “active frequency selective surface material” or AFSS. The AFSS layer can effectively be stretched to provide a lot of absorption but is thin enough to go onto an aircraft. The next layer is a thin metal honeycomb and final is a metal slab.
The good news: the material isn’t locked away in a lab but published openly, so it’s not going to surprise anyone.
Stealth is considered by many to be one of the key technologies that enabled U.S. military dominance throughout the last century, effectively neutralizing, or offsetting, technological gains made by rival nations and the Soviet empire.