Electromagnetic Interference: What Is It? 

Electromagnetic Interference (EMI) is a disruption in the operation of an electronic device due to an electromagnetic field.  EMI can come from natural sources such as lightning and solar radiation and several human causes, including high-powered audio, electric motors, power lines, and radio waves.  EMI can occur due to emissions from transmission sources operating in a Narrow Band or over a Broad Band spectrum.  Radio Frequency Interference (RFI), a subset of the electromagnetic spectrum, most commonly occurs in the 30 MHz to 10 GHz frequency range and can disrupt critical military communication bands. 

EMI severely threatens various critical technologies, including military electronics, navigation systems, medical devices, mobile computers, and communication systems.  

Applications Of EMI Shielding 

EMI Shielding is essential for reliable communication and protection of sensitive information and electronics, especially in military technology. By adding passive components and materials to the system, EMI shielding blocks external electromagnetic interference and prevents devices from picking up spurious signals, which may reduce functionality and security.  By creating a Faraday Cage around the electronic device, Radiated Emissions from the device are also attenuated.

LCD Displays are among the many types of devices susceptible to interference from EMI and are regulated by the military (MIL-STD 461/464) and federal communication (FCC) standards.

Risks associated with not implementing EMI Shielding can include the LCD screen producing distortion, horizontal/vertical lines, or image discoloration.  In addition, radiated signals from electronics can be used to detect and track military troop movements and collect intelligence.   

When there is an interrupted signal due to a lack of shielding, a computer system may experience an operational malfunction, lose sensitive information, or, in severe cases, a complete system failure.  It is imperative that the military maintains open lines of communication and prevents device disruption or detection caused by EMI that could lead to failed missions or casualties.

How Does EMI Shielding Work?

With EMI shielding, the entire electronic system is protected from both external interference and radiated emissions by creating a conductive ground plane.  Electronic display systems, including LCDs, mobile computers, test equipment, and radios used in military, medical, or industrial applications, are protected from EMI via metallic enclosures over the PCB components, electronics, cables, and the LCD. 

For electronic displays, sensors, and camera systems, which require a clear aperture, a transparent conductive shield absorbs the interference source and prevents the signal from reaching the device.

The EMI Shield attenuates radiated emissions from the device and blocks external signals from reaching it, preventing interference in frequency ranges that degrade its functionality.

EMI shield engineering

Cevians EMI Shielding 

The shape, quality, and design of the shield are essential to protect the electronic display system from interference adequately.  With years of development of our proprietary technologies, Cevians’ Clear Shield EMI Windows is considered the industry benchmark.  Their ability to provide high EMI/RFI shielding and high optical transmission in extreme environments has been proven in countless installations in air, shipboard, and ground military vehicles.

Cevians’ line of Clear Shield EMI Windows includes a wide range of transparent and conductive coatings and wire mesh technologies.

Transparent Conductive EMI Windows

Cevians fabricates transparent conductive EMI windows using ITO (indium tin oxide) deposited on glass, polymer or ceramic substrates.  ITO provides a uniform conductive layer with high transmission.  By matching the ITO layer index to the substrate material and exit medium, optical transmission can be further enhanced. 

Wire Mesh EMI Windows 

Cevians’ wire mesh EMI Technology was developed for applications needing higher levels of shielding.  While most shielding needs are met with a transparent conductive coating, certain applications require the increased shielding provided by Cevians mesh technology.  Cevians’ line of EMI meshes is available in various sizes and materials to balance light throughput and EMI shielding requirements.

If you want to learn more about Cevians’ advancements in the realm of EMI Shielding technology and product solutions, our team of experts is available to answer all your questions and provide you with additional documentation.

If you want to learn more about Cevian’s advancements in the realm of EMI Shielding technology and product solutions, our team of experts is available to answer all your questions and provide you with additional documentation here.