Application of EMI Shielding Materials in 5G Base Stations

5G communication electromagnetic waves include two frequency bands, FR1 and FR2. FR1 ranges from 450MHz to 6GHz, while FR2 spans 24.25GHz to 52.6GHz, classified as millimeter waves. Due to the rapid attenuation of these waves in the air, it is necessary to employ ultra-dense networking methods for continuous network coverage. In the future, small and micro base stations will be deployed in crowded areas. To protect human health from electromagnetic radiation, it is crucial to implement electromagnetic shielding for base stations. This can be achieved using efficient electromagnetic shielding materials that absorb or reflect electromagnetic waves, thereby reducing radiation exposure to humans.

Base station enclosures are typically made of aluminum alloy die-casting. For comprehensive electromagnetic radiation protection, the die-casting joints must be connected with conductive silicone strips. These strips form a continuous conductor along the aluminum alloy base station enclosure, using eddy current and reflection effects to confine electromagnetic waves within the base station, preventing leakage and radiation. For 5G high-frequency communication, the shielding effect of conductive silicone strips is mainly realized through eddy current effects. The stronger the conductivity of the material, the more pronounced the eddy current effect. Therefore, to enhance the electromagnetic shielding effect, the material needs to have higher conductivity. Besides conductivity, conductive silicone strips must also meet specific mechanical performance requirements for practical applications. Base station integrators have stringent demands for tensile strength, tear strength, elongation at break, and compression set. Outdoor base stations operate in harsh environments, such as prolonged high temperatures, severe cold, humidity, and corrosive conditions, which can degrade conductive materials. Hence, conductive silicone strips must endure rigorous environmental aging tests.