Application of electromagnetic shielding materials in 5G base stations

5G communication electromagnetic waves include two frequency bands, FR1 and FR2. Among them, the frequency range of FR1 is 450MHz ~ 6GHz, and the frequency range of FR2 is 24.25 ~ 52.6GHz. The FR2 frequency band belongs to the category of millimeter waves. The electromagnetic wave in this frequency band attenuates rapidly in the air, and it is necessary to adopt an ultra-dense networking method to achieve continuous network coverage. In the future, small and micro base stations will be deployed in crowded places. In order to prevent electromagnetic radiation from harming human health, it is very important to perform electromagnetic shielding treatment on the base stations.

The base station shell is generally aluminum alloy die-casting. In order to achieve overall electromagnetic radiation protection, it is necessary to connect the die-casting joints with conductive silicone strips. The conductive silica gel strip forms a continuous conductor of the aluminum alloy base station housing, and the eddy current effect and reflection effect of the conductor confine electromagnetic waves inside the base station, thereby preventing electromagnetic wave leakage and radiation. For 5G high-frequency communications, the electromagnetic shielding effectiveness of conductive silicone strips is mainly achieved through the eddy current effect. The stronger the conductivity of the material, the more obvious the eddy current effect. Therefore, in order to improve the electromagnetic shielding effectiveness, the material needs to have higher conductivity Sex. In addition to conductivity, conductive silica gel strips must meet specific mechanical properties to meet practical application needs. For example, base station integrators have strict requirements on tensile strength, tear strength, elongation at break, and compression set. The working environment of outdoor base stations is relatively harsh, such as long-term high temperature, severe cold, humidity and corrosive environments, which may cause deterioration of conductive materials. Therefore, conductive silicone strips must be able to withstand strict environmental aging tests.

In addition to the overall shielding of the base station housing with conductive rubber strips, the electronic components inside the base station also need to be partially electromagnetic shielded to prevent signal interference. The Form in place (FIP) process can accurately apply conductive adhesive to the required parts. The process is simple, can be formed on complex surfaces, and has high material utilization, which is very suitable for local electromagnetic protection of base station equipment. Use the FIP process to apply the conductive adhesive on the required parts, and form a conductive and elastic "wall" after curing, which acts as a partial shield.


Electromagnetic shielding materials commonly used in communication base stations include electromagnetic shielding sealing strips, electromagnetic shielding conductive adhesives, electromagnetic shielding gaskets, etc.

Publication Date: 2 September, 2020

Category: Electromagnetic Material

Tags: EMC

Authors: Konlida

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