Radomes are structures that cover antenna systems and radar equipment to provide protection from the environment. A key requirement for these radomes is that the material they are made of must be radiotransparent so that signals can pass through them. The value of 5G lies in its ability to use much higher signal frequencies to enable lower latency and higher speeds for 5G solutions. The drawback is that high frequencies cannot easily penetrate materials, which restricts the range of connected devices.
Therefore, radomes must be manufactured from materials with low attenuation that allow higher frequencies to penetrate. Composite materials, such as fiberglass, help mitigate signal attenuation while providing the necessary mechanical strength for durable protective radomes.
Exel Composites' new patent includes a closed-cell thermoplastic foam in its structure.
"We used foam in the design because of its low density and rigidity, which facilitate the transmission of radio waves. By combining it with fiberglass skins, which provide mechanical strength, we have created a durable, rigid material capable of offering the environmental protection that antennas require."
“This patent is important because it offers a custom-made window that allows wavelengths to penetrate more easily,” says Kim Sjödahl, Senior Vice President of Technology and R&D at Exel Composites. “Instead of manufacturing the entire radome with the same material density, we can modify it according to customer requirements so that there is a specific insert that creates the necessary window for the passage of radio waves.”.
“We’ve worked closely with antenna manufacturers to optimize the radome design based on the antenna’s functionality and frequency,” explains Pesonen. “Depending on these factors, we can modify the combination of fibers, resin, and foam to improve specific properties. For example, to create greater mechanical strength or attenuation in the necessary areas.”.
"It has taken us four years to extend the patent to Europe since its development, which demonstrates the complexity involved in the manufacture of radomes," Pesonen continues.
"Frequencies have increased over the last decade, with 5G standards reaching 39 gigahertz (GHz). Our manufacturing capabilities and materials expertise allow us to be ready for even higher frequencies, such as those of the 6G of the future.".