What is Electromagnetic Interference (EMI) And How to Tackle It?

In this digital era, our world is constantly humming with the buzz of electromagnetic interference (EMI), with millions of devices and appliances of daily use creating these disturbances ever so often. Sure, we cannot feel this electromagnetic interference in our tangible lives, but many of your cherished electrical and electronic devices continue to bear the brunt of it.

Why is it a concern? Well, too much of nothing is good, and the same rings true for your devices- leave a machine vulnerable to too much interference, and you will see severe issues cropping up in both performance and reliability. Usually, device manufacturers design their products with a built-in system to bring down, if not eliminate, the ill-effects of EMI, and these shielding systems take on the responsibility of employing multifarious methods to protect your appliances and devices.

Are you someone who manufactures, designs, or simply uses devices sensitive to EMI? If so, it might pay off to know a little about how the phenomenon works and how to deal with it best. Not many people know this, but nature itself can lead to EMI; thunderstorms, solar storms, and such are the greatest examples of that. These are natural emitters of electromagnetic radiation, and can leave a detrimental impact on electrical devices. Among the various types of EMI that affect devices, radio frequency interference (RFI) which occupies the radio frequency band of the electromagnetic spectrum, is one of the most common. If you have tons of power switching equipment or electric motors at hope, you might want to watch out.

Consequences of Electromagnetic Interference (EMI)

Here are some of the most common consequences of EMI and RFI:

  • Video and audio signal distortion
  • Challenges in establishing wireless connections
  • Interference with monitoring and control systems
  • Overheating or fires, in extreme cases
  • General technological difficulties and malfunctions

Which Devices Are Vulnerable to EMI?

Here is a brief list of devices that are the most vulnerable to EMIs:

  • Wi-Fi routers
  • Medical devices
  • Computers
  • Smartphones
  • GPS systems
  • Baby monitors
  • Broadcast television
  • Walkie-talkies
  • AM and FM radio

Here’s the irony of the situation- often, the devices that are the most vulnerable to EMI are also  the ones most susceptible to it. Part of what is oftentimes so frustrating about troubleshooting EMI related problems is that the phenomenon is a two-way street, where devices are able to both transmit as well as receive interference.

A Final Few Things to Note About EMI

Devices such as WiFi routers or key fobs require the ability to wirelessly transmit RF signals, so metal and similar kinds of enclosures that block EMI might also block the necessary transmission that these devices rely on. Polycarbonate shielding enclosures can be a viable solution for these situations.

Seams or gaps that are yet to be properly secured can compromise the enclosure’s shielding performance, so beware of even the smallest of apertures that can serve as antennas for EM radiation to enter or leave. Enclosures with continuous body designs might be of help.

Lastly, the ground is often a source of persistent EMI, since frequencies in a high-impedance ground might create a “noise voltage” which can prove to be tough to eliminate. Low-impedance grounding techniques might be of help here.

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