Mitigate Electromagnetic Interference with EMI & RF Shielding Materials

Posted by Alex Zhang on February 9, 2022

Electromagnetic interference (EMI) can disrupt the performance of electronic equipment. A variety of natural and manmade sources cause EMI, from lightning and solar flares to electric motors, generators, and transformers, to microwave ovens and fluorescent lights. One of the most common manifestations of EMI is radio frequency (RF) signal loss, which can impact Wi-Fi and Bluetooth connections.

IT equipment also generates RF signals, and that can create security risks. If cybercriminals are able to intercept and analyze the RF signals emanating from the equipment, they could gain access to systems and steal data. This is a real threat in government, military, and other highly sensitive environments.

EMI and RF shielding materials can prevent both problems. There are a number of factors to consider when choosing the right material, including effectiveness, cost, and resistance to corrosion.

EMI and RF Shielding Materials

One of the first questions asked when exploring electromagnetic shielding is, “What materials block EMI and RF signals?" Well, the most commonly used EMI and RF shielding materials include copper, aluminum, and steel. Each has different properties that can influence the selection. One of the main properties influencing the level of EMI/RF shielding in materials is reflection. Reflection attenuates the electrical part of the interference. To achieve EMI reflection, the material used for shielding needs to have mobile charge carriers. What does this mean in simple terms? The material used should be highly conductive.

Copper Shielding

Copper is highly conductive, making it an effective shield against EMI and RF. It can be manufactured into a wide range of shapes and installed quickly. It is also durable and resistant to oxidation. Although it can be expensive, it is generally considered the best EMI and RF shielding material. It is widely used in everything from MRI facilities to IT equipment.

Copper alloy 770, also known as alloy 770 and nickel silver, is an alloy of nickel, copper, and zinc. It resists corrosion and works well at shielding frequencies in the mid-kilohertz to gigahertz range.

Aluminum Shielding

Aluminum is another great EMI/RF shielding material. It is about 60% as conductive as copper, but it holds other unique properties that make it a great choice. It is malleable, has a high strength-to-weight ratio, and is great at thermal and electrical conductivity. Aluminum is also less expensive than copper. Aluminum can be subject to galvanic corrosion and oxidation, but that threat can be mitigated by limiting its exposure to the elements and through consistent maintenance. When you consider efficacy combined with price and weight, it is hard to beat aluminum for EMI/RF shielding.

Steel Shielding

Steel is the least effective of the three materials in terms of signal attenuation. Cold rolled steel offers better EMI and RF shielding properties than other types. Pre-tin plated steal works well across a wide range of frequencies, and the tin plating helps prevent corrosion. It is a good low-cost alternative and also offers the magnetic shielding properties that copper and aluminum lack.

DefenseShield from Enconnex

Shielding against EMI and RF at the data center level is expensive. A better approach is to utilize properly shielded cabinets. Enconnex developed the DefenseShield Electromagnetic Compatibility (EMC) Hardened Enclosure to deliver military-grade performance in a lightweight, cost-effective solution.

DefenseShield is purpose-built to provide 85dB of attenuation against EMI and RF signals from 1MHz to 10GHz (DefenseShield 5G provides 75dB at 1MHz-40Ghz). It enables you to isolate sensitive systems and data from threats such as EMI and power analysis side channels. Our DevShield product is nearly identical in form and creates a real device application test environment that can support hundreds of devices in a single enclosure. Simply add more cabinets to scale from an R&D lab to a data center with thousands of devices.

But DefenseShield is more than just a Faraday cage. It offers key features that reduce costs and simplify management. Fifty percent lighter than competitive products, DefenseShield is easy to ship, install and integrate into the data center. It also provides the airflow needed to support high-density applications, with ten powerful, long-life fans.

Customize your enclosure with a variety of power options, shelves, and other components from Enconnex. We’re here to help you minimize the impact of electromagnetic interference and meet your most demanding requirements. Reach out to an expert today.

Posted by Alex Zhang on February 9, 2022

Alex has 10+ years of experience working in the data center and material science industries. He currently serves as product manager at Enconnex for our real device testing and RF shielded product lines. Previously, he managed our sheet metal products. He has his MSEE degree from Northwest Polytechnic University and holds numerous professional certifications.

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