Problem and solution

Land, air and satellite-based radar systems pose a major threat to the armed forces. They detect objects that reflect radar signals, such as tanks, trucks and planes, depriving troops of both cover and the element of surprise. Various camouflage systems are used to counter this, but one of their main disadvantages is that they neutralize not only enemy radar waves, but also GPS signals and useful radio waves used for voice communications.

If you are under a traditional multi-spectrum network and want to communicate via radio, you often need to place an antenna outside the network to bypass the wide spectrum protection and receive a signal. You also run the risk of exposing yourself to the enemy, which isn’t an ideal option, especially if you’re reconnaissance on the front lines. If GPS is used, you may need to take the entire GPS device offline, leaving you even more vulnerable.
– says Johan Yersblad, senior development engineer at Saab.

The new development, known as the Frequency Selective Surface System, or FSS, allows users of custom-built ULCAS networks to use radio and GPS systems without restrictions while remaining completely anonymous. The company also claims that the mesh uses special pigments that help prevent the system from being detected by near- and shortwave infrared sensors (i.e. thermal imagers). It also provides protection against radar reconnaissance and guided missiles in the 1-100 gigahertz range.

Demonstration clip: video

Lattice structure is the key to the system

Yersblad explains that the problem with traditional multispectral grids is that enemy radar systems, radio communications, and GPS rely on electromagnetic waves. The materials used to attenuate radar waves in traditional multispectral networks block not only traditional radar frequencies but also a broad spectrum of radio waves.

“Following an inquiry from a potential customer, we began exploring the potential of networks focused on absorbing the high-frequency electromagnetic waves used by radar systems rather than the broader spectrum.”says. “The result of this work was a cloaking system in which a material that attenuates radar waves is arranged in a grid pattern. The size and shape of the grid absorbs high-frequency radar waves but allows radio waves to pass through it easily.”.

The ULCAS FSS grid produced by this study is very similar to conventional grids. Looking at it, you will not be able to tell the difference between a ULCAS network with FSS and the normal network of the same company. They have the same appearance and weight, have the same visual and thermal characteristics.

Although the primary application of FSS is to pass radio waves, not radar signals, other results can be achieved by changing the “pattern design”.

For example, we cannot pass the radio waves of communications and the radio waves of radars by changing the directional pattern. This can be useful if you have a radar operating under the grid.
– says Johan Yersblad.

The company does not offer the full production technology of its innovation. The FSS system is currently undergoing final testing with the aim of being released in 2023. Field tests have already proven its effectiveness in passing through useful electromagnetic spectrums and cutting out undesirable ones.