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Electromagnetic Compatibility (EMC) is the branch of electrical sciences which studies the unintentional generation, propagation and reception of electromagnetic energy with reference to the unwanted effects that such an energy may induce. To this purpose, the goal of EMC is the correct operation, in the same electromagnetic environment, of different equipment which involve electromagnetic phenomena in their operation.

In order to achieve such an objective, EMC pursues different issues: emission issues, in particular, are related to the reduction of unintentional generation of electromagnetical energy and/or to the countermeasures which should be taken in order to avoid the propagation of such an energy towards the external environment, susceptibility or immunity issues, instead, refer to the correct operation of electrical equipment in the presence of electromagnetic disturbances.

Noise mitigation and hence electromagnetic compatibility is achieved by addressing both emission and susceptibility issues, i.e., quieting the sources of interference, making the disturbance propagation path less efficient, and making the potentially victim systems less vulnerable.

When the propagation of electromagnetic disturbances in guiding structures, i.e. conductors, transmission lines, wires, cables, printed circuit board (PCB) traces, is by a guided propagation mechanism, conducted emission and susceptibility issues are considered, whereas, when open-space propagation of electromagnetic disturbances is addressed, the point of focus becomes radiated emission and susceptibility phenomena.

Contents 1 History 2 Regulatory agencies and organizations 3 See also 4 External links

In the past, outside of the military field, EMC was not of paramount importance to equipment manufacturers and there was a relaxed EMC regime. However, because of the proliferation of the clocks that synchronize modern digital circuits, the concomitant increase in their switching speeds, and the lower voltages they began using, EMC increasingly became a source of concern.

Many nations became aware of EMC as a growing problem and issued directives to the manufacturers of digital electronic equipment, which set out the essential manufacturer requirements before their equipment could be marketed or sold. Organizations in each nation were set up to draw up and safeguard these directives.

Among the more well known national organizations are:

The Federal Communications Commission for the United States; CEN (Comité Européen de Normalisation or European Committee for Standardization); CENELEC (Comité Européen de Normalisation Electrotechniques or European Committee for Standardization); ETSI (European Telecommunications Standards Institute) for Europe; and BSI (British Standards Institution) for Britain.

There are also several international organizations who try "to promote international co-operation on all questions of standardization" (harmonization), including EMC standards.

The most important international organization is the International Electrotechnical Commission (IEC), which has several committees working full time on EMC issues.

These are Technical Committee 77 ("TC77") working on "electromagnetic compatibility between equipment including networks", and the CISPR (Comité international spécial des perturbations radioélectriques or International Special Committee on Radio Interference).

Co-ordination of the IEC's work on EMC between these committees is the responsibility of the ACEC, the advisory committee on EMC.

• EMC Fundamentals
• BS3G100 military EMC specification
• spread spectrum
• List of EMC directives
• Notable EMC Personalities
• Television interference
• EMC Aware Programming
• Emission Aware Programming
• Immunity Aware Programming

• EMC Design Guidelines
• Analog, RF & EMC Considerations in Printed Wiring Board Design
• EMC compliance FAQ
• EMC Design Fundamentals
• a .PDF with practical information on EMC testing
• Links and Resources for EMC Testing
• Federal Communications commission
• Information about EMC / EMI testing
• About the U.S. Telecommunication Certification Body
• About European EMI and EMC Conformity Assessment
• IEEE EMC Society, Orange County, CA, chapter
• Brisitsh Standards Institute EMC Testing
• UK EMC Compliance Club - home of the EMC Journal