What is EMI Shielding and Why is it Important for Your Design?

Electromagnetic interference (EMI) can disrupt electronic devices, equipment, and systems that are used in critical applications.

Examples include medical, military, and aerospace electronics; mass transit systems; industrial touch screens; and navigation and vehicular control systems – just to name a few.

The causes of EMI are numerous, and include both man-made and natural sources. The results can range from temporary disturbances and data losses to system failure and even loss of life.

For engineers, it’s important to recognize how electromagnetic energy (EME) in the application environment can cause interference.

Without this basic EMI awareness, you may design gaskets that lack adequate protection against electromagnetic fields in the radio frequency (RF) spectrum, the part of the electromagnetic spectrum with frequencies from 3 kHz to 300 GHz. RF waves form the basis of radio technology, but they can also transmit signals that interfere with wireless communications.

Sources of EMI

In general, EMI sources can be divided into two major categories: ambient EMI and power quality problems.

Railroad and mass transit systems, medical equipment, and military applications also face their own specific challenges.

Increasingly, intentional EMI (IEMI) also represents a threat to non-military assets such as the power grid and other types of critical infrastructure.

• Railroad and mass transit systems may experience EMI because of application-specific factors such as:

1. Emissions from train control and propulsion systems

2. High voltage contact switching

3. Third rail shoes

4. Train signaling and control systems

• Medical equipment is susceptible to EMI, too. Application-specific sources include:

1. Electrical and electronic equipment in surgical units

2. Life support devices such as ventilators and infusion pumps

3. Patient telemetry and assistance equipment

4. X-ray machines for diagnostics and therapeutics

• In addition to IEMI (colloquially called “electronic warfare”), military assets and critical infrastructure face EMI threats such as:

1. High-altitude nuclear electromagnetic pulse (HNEMP) High-power microwave weapons

2. E-bombs

3. EMP cannons

Some of these threats are extreme, of course, but all engineers need to assess EMI risks in order to incorporate appropriate protection into their gasket designs.

Gaskets for Shielding as Solution from Lambda India

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LAMBDA INDIA