Materials for 5G communication

Radomes protect antenna systems from damage in harsh conditions such as rain and snow. Composite materials have been used in previous generations of radomes and allow manufacturers to achieve a balance between mechanical strength and signal permeability.

However, 5G typically operates at much higher frequencies than 4G, including low-band 5G above 3 GHz, mid-band frequencies in the sub-6 GHz range and the millimeter wave range of 24 GHz and above. As bandwidth increases, it becomes increasingly difficult for manufacturers to develop radomes that are radio transparent and still withstand the wide range of weather conditions.

The need for better radio transparency brings new requirements for radomes and the composite materials used in their construction. Fiberglass-reinforced materials have been successfully used in cell towers up to 4G LTE, but the same composite construction will not provide the same performance in systems operating at higher 5G frequencies.

To achieve a balance of radio transparency and mechanical strength, Exel Composites developed both a composite material and a manufacturing process, resulting in the development of radomes with better signal transmission, stiffness and structural integrity. One improvement was the integration of a thermoplastic foam layer between the composite top layers. This middle layer has a much lower dielectric constant than the surface layers, giving the solution better radio transparency. It is also possible to integrate other dielectric materials such as honeycomb and cork into thin GRP walls of the parts of the radome optimized for antenna design.

Radomes, composites and recyclability

What can be done with composite radomes at the end of their life when older generations of antennas are replaced? According to Exel, there is no clear answer, but if there is a desire to reduce the_{carbon footprint} and recycle, it is possible to recycle composite materials at the end of their life.

One method is pyrolysis, in which glass fiber-reinforced plastic is broken down into three recyclable structures: Pyrolysis gas, pyrolysis oil and a solid as a by-product. Other methods, in which composite materials are crushed and mixed into fuels for cement kilns, can also be used. However, these methods are not as widespread, so companies have to transport their waste over long distances for recycling. Exel Composites is working with various industry associations, such as the European Composites Industry Association, to investigate recyclability.