EMC

Introduction

ElectroMagnetic Compatibility (EMC) is a characteristic of electrical and electronic equipment that permits it to operate as intended in the presence of other electrical and electronic equipment, and not to adversely interfere with that other equipment.

All such equipment emits electrical energy, and some of that emitted energy may interact and interfere with other equipment. Equally, equipment may be susceptible to receiving energy emitted from other sources. Obviously, radio transmitters and receivers are intended to emit and receive electrical energy, but other equipment may not be intended to do so.

Even transmitters and receivers may emit and receive unwanted energy that may prevent those devices, or others, from functioning as intended. It is part of the EMC 'art' to design and operate equipment so that it is both prevented from emitting spurious energy that can cause interference, and is immune to the adverse effects of any spurious energy that it may receive.

EMC regulation

As the effects of interference have severe consequences, EMC is frequently a subject of national and international regulation. Within Europe, EMC regulation is managed mainly through the European Commission's EMC Directive (89/336/EEC, subsequently revised as 2004/108/EC). However, there are many types of equipment that are excluded from the EMC Directive, although EMC requirements for most of them are included in other Directives and regulations. Here are some examples:

• Equipment covered by the Radio and Telecommunications Terminal Equipment (R&TTE) Directive
• Certain aeronautical items
• Automotive components
• Medical devices, including implantable devices
• Marine equipment
• Amateur radio equipment not available commercially.

The EMC Directive and many of the other relevant Directives are 'New Approach' Directives. As such, they rely for their operation on Harmonized Standards developed by recognized European standards bodies, such as ETSI. Harmonized Standards define technical characteristics which can be used to demonstrate compliance with the essential requirements of the Directive.

In the case of the EMC Directive, the essential requirements are that equipment shall be designed and manufactured such that:

• the electromagnetic disturbance it generates does not exceed a level allowing radio and telecommunications equipment and other apparatus to operate as intended; and
• the apparatus has an adequate level of intrinsic immunity to electromagnetic disturbance to enable it to operate as intended.

Equipment which meets Harmonized Standards is presumed to comply with the essential requirements, and a manufacturer may declare conformity with the Directive. Alternatively, manufacturers may choose to request certification of equipment by a recognized third party, known as a 'Notified Body'.

Our Role & Activities

ETSI has a cooperation agreement with CENELEC for the production of EMC standards, under which:

• EMC for Telecommunications Terminal Equipment is standardized by CENELEC
• EMC for Telecommunications Network Equipment is standardized by ETSI
• EMC for Radio Equipment and Systems (including radio telecommunication terminal equipment) is standardized by ETSI.

EMC standards for telecommunications network equipment

ETSI has the following EMC standards for Telecommunications Network Equipment

• EN 300 386, a Harmonized Standard for telecommunications network equipment
• ES 201 468, a standard providing additional requirements for enhanced availability of service.

EMC standards for radiocommunications equipment

ETSI has created a multi-part EMC standard (EN 301 489) for EMC for radio equipment, in accordance with the R&TTE Directive.

Part 1 of EN 301 489 covers EMC requirements that are common to all radio equipment. The subsequent parts specify additional requirements that are specific to a particular radio service. These include mobile and aeronautical communications, TV broadcasting, satellite services, medical devices and radars.

Marine radio is treated separately. Equipment subject to carriage requirements under the International Maritime Organization (IMO) convention for Safety of Life at Sea (SOLAS) are covered by the Marine Equipment Directive, and the related ETSI standards for this purpose contain EMC, radio and environmental requirements in one document.

Other marine equipment is subject to the R&TTE Directive. The EMC requirements are included in EN 301 843, which follows a similar structure to EN 301 489 for land-based equipment.

Electrical equipment (including telecommunications equipment) intended to be fitted to a motor vehicle is required to meet Automotive EMC requirements. These requirements are set out in Directive 2004/104/EC, a specific Directive which forms part of European legislation for automotive type approval. Relevant EMC requirements for radio communications equipment in motor vehicles are covered by the EN 301 489 series of standards. ETSI has also produced a guide (EG 202 414) for the automotive industry on how to demonstrate conformance of 'after market' radio communications equipment to the Automotive EMC directive.

International activities

ETSI is a member of the Steering Committee of CISPR, the International Special Committee on Radio Interference. This Steering Committee makes the strategic and policy decisions for CISPR. ETSI members are very active in CISPR sub-committee I which writes the global EMC standards for Information Technology equipment and telecom terminal equipment. CISPR I determines the radio-frequency emission limits for all telecommunications equipment which are then incorporated into the ETSI EMC product standards. ETSI also participates in the International Electrotechnical Commission (IEC) Advisory Committee on Electromagnetic Compatibility (ACEC), which co-ordinates EMC standardization in IEC.

Standards

The following is a list of recently published and frequently downloaded standards. Please use the ETSI Work Programme to find further related standards.