EMC, or Electromagnetic Compatibility, testing is a critical step in the product development process for any electronic device. EMC testing ensures that the device does not emit excessive electromagnetic radiation that could interfere with other devices and also ensures that the device is not susceptible to electromagnetic interference from other devices. This article will cover the basics of EMC testing for product development.

Why is EMC Testing Important?

Electromagnetic radiation is present all around us, and every electronic device emits some form of radiation. If the radiation emitted by an electronic device is too high, it can interfere with other devices in the environment. For example, a mobile phone emitting too much electromagnetic radiation could interfere with an airplane’s navigation system, which could be dangerous. EMC testing ensures that electronic devices are safe to use and will not interfere with other devices.

EMC testing also ensures that electronic devices are not susceptible to electromagnetic interference from other devices. A device that is susceptible to interference may not function correctly, leading to potential safety hazards or product failures. By conducting EMC testing, product developers can identify potential sources of interference and take steps to reduce or eliminate them.

Types of EMC Testing

There are two main types of EMC testing: emissions testing and immunity testing.

Emissions Testing

Emissions testing, also known as radiated emissions testing, is used to measure the amount of electromagnetic radiation that a device emits. This type of testing is performed in an anechoic chamber, a room designed to be completely free from external electromagnetic interference. The device being tested is placed in the center of the chamber, and a specialized antenna is used to measure the amount of radiation it emits. The emissions are measured across a range of frequencies, and the results are compared to the limits set by regulatory bodies such as the Federal Communications Commission (FCC) in the United States.

Immunity Testing

Immunity testing, also known as susceptibility testing, is used to measure how well a device can operate in the presence of electromagnetic interference. This type of testing is also performed in an anechoic chamber, but instead of measuring emissions, the device is subjected to controlled electromagnetic interference at various frequencies and intensities. The device’s performance is monitored, and any issues are noted. The results are compared to the requirements set by regulatory bodies.

EMC Testing Standards

EMC testing is governed by various national and international standards, such as those set by the International Electrotechnical Commission (IEC), the European Union’s Conformité Européenne (CE) marking, and the FCC in the United States. Compliance with these standards is essential to ensure that electronic devices can be sold and used safely around the world.

Conclusion

EMC testing is a crucial step in the product development process for electronic devices. It ensures that devices are safe to use, will not interfere with other devices, and are not susceptible to electromagnetic interference. By conducting EMC testing, product developers can identify potential sources of interference and take steps to reduce or eliminate them. Compliance with national and international standards is essential to ensure that electronic devices can be sold and used safely around the world.

All CE marked products are required to demonstrate compliance to EMC emissions and immunity standards. Early EMC testing is always recommended on any new design and we have found that this is the key to managing low risk product development.

Considering EMC needs early on in the design ensures that the ground plane construction and partitioning is intrinsically low noise, board interconnects and cabling are optimised in terms of screening and termination, radiative and sensitive electronics are isolated and mechanical encapsulations are appropriately shielded.

Where all these considerations are planned proactively, the risks of last minute retrospective design changes can be mitigated as they can be very disruptive to schedule and development cost.