Fibreglass is a common type of fibre-reinforced plastic using glass fibre. The fibres may be randomly arranged, flattened into a sheet (called a chopped strand mat), or woven into a fabric. The plastic matrix may be a thermoset polymer matrix—most often based on thermosetting polymers such as epoxy, polyester resin, or vinylester—or a thermoplastic.
Cheaper and more flexible than carbon fiber, it is stronger than many metals by weight, is non-magnetic, non-conductive, transparent to electromagnetic radiation, can be molded into complex shapes, and is chemically inert under many circumstances.
Fibreglass in Telecommunications
In telecommunications, GRP is often used to construct radomes, which are protective enclosures for antennas. The primary role of a radome is to shield sensitive antenna equipment from external environmental elements such as wind, rain, ice, or even bird strikes, while not significantly impeding the antenna's reception or transmission abilities.
One of the primary reasons GRP is a suitable material for radomes is due to its favourable electromagnetic properties. The effectiveness of a radome is heavily dependent on its transparency to radio frequency (RF) signals. Ideally, a radome should have minimal impact on the signal passing through it; this characteristic is often referred to as being "RF transparent". GRP is a near-perfect RF transparent material, meaning it has minimal signal loss and does not greatly affect the phase of the transmitted or received signal. This characteristic ensures that the antenna within the radome can perform optimally, minimising any potential degradation in performance due to the protective enclosure.
GRP radomes also benefit from being highly durable and weather resistant. Their inherent resistance to UV radiation and various weather conditions makes them ideal for outdoor telecommunications infrastructure, where they may be exposed to harsh elements. Furthermore, they offer a good balance between cost, weight, and strength, making them a practical choice in many scenarios.