Electromagnetic fields are found in almost all environments. They can be produced by a range of manmade devices, including power lines, electrical wiring and electronic devices, as well as by natural sources such as lightning, solar activity and Earth’s natural magnetic field.

When electromagnetic energy affects electronic equipment, it’s referred to as electromagnetic interference (EMI). This type of interference can affect the functioning of electronic equipment and potentially lead to disruptions in communications, false reading and safety issues.

If you’re developing an electronic device, you’ll likely need to use electromagnetic shielding to ensure it has good electromagnetic compatibility (EMC) performance.

Shielding protects your device from electromagnetic fields, allowing it to function properly even when it’s exposed to electromagnetic waves. It’s vital for ensuring your device functions reliably and complies with EMC regulations, such as the FCC’s Part 15 rules in the United States.

As an ANSI-accredited electronics testing lab, we specialize in testing electronic devices of all types, and can help you to achieve regulatory compliance for EMC.

You can ask our engineers a question about electromagnetic compatibility, or request a quote for testing and certifying your device, by contacting us online or calling us at 866-540-5287.

You can also continue reading to find out more about what electromagnetic shielding is and the key role it plays in ensuring your device complies with EMC regulations. 

What Are Electromagnetic Fields?

Electromagnetic fields are fields made up of electrical and magnetic components. They spread as waves, which are generated through movement of charged particles. Electromagnetic fields can be man-made (generated by electronic devices or equipment) or natural.

Common man-made sources of electromagnetic fields include power lines, electrical wiring in a building or other structure, electronic devices, medical equipment, broadcasting equipment and devices that allow for wireless communication, such as phones or Wi-Fi routers.

Common natural sources of electromagnetic fields include solar flares, lightning strikes, Earth’s magnetic field, auroras, and radio waves emitted by the sun and other stars. 

Electromagnetic Waves and Electronic Devices

Electromagnetic waves often cause electromagnetic interference, meaning they interfere with the functioning of electronic devices.

As electromagnetic energy passes through an electronic circuit, it can induce voltages and/or currents within the circuit. Electromagnetic waves can also cause interference from magnetic and capacitive coupling, which can introduce noise and signals into equipment.

In some cases, the internal conductive components of a device may act as antennas, causing the device to pick up unwanted electromagnetic waves from its environment. 

When electromagnetic waves are transmitted at a high frequency, they cause radio frequency (RF) interference. This can cause devices to stop functioning correctly, and may affect certain types of communication between devices. 

Electromagnetic Waves and EMC

Because of its effects on device reliability and function, electromagnetic interference is a key aspect of EMC regulations. Regulations such as FCC Part 15 set performance requirements, including a device’s electromagnetic immunity (ability to withstand electromagnetic waves). 

In order to receive FCC equipment authorization and bring your electronic device to market, it needs to demonstrate sufficient immunity in an accredited testing laboratory.

Your device must also pass other tests, such as radiated emissions and conducted emissions testing, to verify that it does not emit significant amounts of radio frequency energy itself.

Our team can explain this process to you and provide a quote for preparing your device and completing testing. Contact us now to talk to our team, ask a question, and/or request a free quote.

How Electromagnetic Shielding Works

Electromagnetic waves exist in almost every environment. Because of the impact that these waves can have on the functioning of electronic devices, it’s critical that your device has the correct amount of shielding to protect it from interference.

The process of electromagnetic shielding involves using conductive materials to either reflect, absorb or dissipate electromagnetic waves. This stops electromagnetic energy from entering into your electronic device and causing changes in its functioning and performance. 

At a simple level, electromagnetic shielding involves creating a physical barrier that stops any unwanted electromagnetic signals from entering your device. 

Common EMI Shielding Materials

Several materials are used in electromagnetic shielding. These materials are conductive and magnetic, allowing them to block electromagnetic fields and allow your electronic device to function normally when it’s exposed to electromagnetic fields. 

Conductive shielding materials, such as copper, aluminum and silver, can reflect and absorb electromagnetic waves. When an electromagnetic wave hits a conductive surface, it induces currents in the material, which produce their own EM fields that counteract the wave.

These materials also dissipate unwanted electromagnetic energy as heat, which also blocks electromagnetic waves from passing through the shield. 

Magnetic materials, such as ferrite and nickel-iron magnetic alloy, provide protection against electromagnetic interference by attracting magnetic fields and channeling them to the path of low resistance. This reduces the strength of magnetic fields inside your device. 

Many devices use a combination of conductive and magnetic shielding materials to achieve a high degree of shielding across the widest possible frequency range. These materials can be used in a range of forms in your device, including enclosures, coatings and protective foils. 

Because devices vary in their design and EMC performance, there’s no one-size-fits-all way to use shielding, or perfect shielding material, for every type of device. Our engineers can review your device’s design and recommend the most appropriate solution for your needs.

Electromagnetic Shielding and FCC/CE Compliance

Because of the key role electromagnetic shielding plays in protecting your device from outside electromagnetic fields, it’s a key part of achieving regulatory compliance for your device.

All major markets, including the United States and the European Union, have strict regulations that apply to devices capable of using the radio frequency spectrum. 

These include FCC Part 15 in the United States, and the Electromagnetic Compatibility (EMC) Directive and Radio Equipment Directive (RED) regulations in the European Economic Area. 

Other countries also have laws for devices that interact with the radio frequency spectrum. For many markets, these laws are based on specific IEC standards for electronics.

Electromagnetic shielding plays a key role in the process of complying with regulations. This is because effective shielding not only protects your device from electromagnetic waves created by other devices, but also prevents its own electromagnetic radiation from exiting the device. 

This is critical for complying with FCC, CE and/or other regulations for radiated and conducted emissions, as well as general electromagnetic immunity.

Get Expert Help With EMC Shielding for Your Device

If you’re in the process of developing an electronic device and need expert assistance reducing emissions and improving immunity, our experienced team of engineers can help you.

As an ANSI-accredited testing lab and FCC-recognized Telecommunications Certification Body (TCB), we help hundreds of electronics manufacturers around the world comply with FCC, CE, ISED and other EMC regulations to achieve global market access.

Our team of expert engineers can review your device’s design, provide pre-compliance testing, and provide EMC consulting services to help you improve your device’s EMC performance and successfully pass regulatory compliance testing.

To request a quote for your project, or to ask our engineers any questions you may have about shielding or any other aspect of EMC compliance, contact us online or call us at 866-540-5287.