The application of electromagnetic shielding materials in 5G base stations

5G communication utilizes electromagnetic waves in two frequency bands: FR1 and FR2. FR1 ranges from 450MHz to 6GHz, while FR2 ranges from 24.25GHz to 52.6GHz, falling under the millimeter wave category. Electromagnetic waves in the FR2 band decay rapidly in air, necessitating ultra-dense networking for continuous coverage. Future deployments will include small and micro base stations in crowded areas. Effective electromagnetic shielding of base stations is crucial to prevent potential health risks from electromagnetic radiation.

The base station casing typically uses aluminum alloy die-casting for overall electromagnetic radiation protection. Connecting the die-cast joints with conductive silicone strips creates a continuous conductor throughout the aluminum alloy housing. This setup utilizes the eddy current and reflection effects to confine electromagnetic waves within the base station, preventing leakage and radiation. In 5G high-frequency communication, conductive silicone strips achieve electromagnetic shielding primarily through the eddy current effect. Higher conductivity enhances this shielding effect. Apart from conductivity, these strips must meet specific mechanical requirements for practical use. Base station integrators demand high tensile strength, tear resistance, elongation at break, and resistance to compression set. Outdoor base stations face harsh conditions such as high temperatures, extreme cold, humidity, and corrosive environments, necessitating conductive silicone strips that can withstand rigorous environmental aging tests.

Aside from employing conductive rubber strips for overall shielding of the base station casing, the electronic components within the base station also require localized electromagnetic shielding to prevent signal interference. The Form-In-Place (FIP) process precisely applies conductive adhesive to specific parts. This method is straightforward, capable of conforming to complex surfaces, optimizes material usage, and is highly suitable for localized electromagnetic protection of base station equipment. After curing, the FIP process forms a conductive elastic "wall" that acts as partial shielding around the necessary components.

Commonly used electromagnetic shielding materials in communication base stations include electromagnetic shielding sealing strips, conductive adhesives for shielding, electromagnetic shielding gaskets, and more.