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 that it is immune to the adverse effects of any spurious energy that it may receive.
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, electrical equipment (including telecommunications equipment) intended to be fitted to a motor vehicle are considered to be 'Electronic Sub Assemblies (ESA)' and are 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. The annexes of this Directive contain all the technical requirements necessary to demonstrate conformance which allows the ESA to be placed on the market.
The Directive covers two categories of after market equipment ESAs:
a) After market equipment intended for installation in a motor vehicle, and which are not related to immunity related functions of the motor vehicle. As a general rule these are ESAs which are not related to an immunity-related function of the motor vehicle, are connected directly to the vehicle's dc supply, and are not involved/related with any of the vehicle functions (described in Annex 1, clause 2.1.12 of the Directive).
b) After market equipment intended for installation in a motor vehicle, and which is related to immunity related functions of the motor vehicle, as set out in Annex 1, clause 2.1.12 of the Directive, is subject to full type approval requirements of the Directive.
The Automotive EMC Directive recognizes conformity according to the procedures of the EMC Directive and the R&TTE Directive (1999/5/EC). This includes the CE marking for after market ESAs described in category a) above, but additionally requires that the limits of the clauses referenced in Annex 1, clause 3.2.9 of the Automotive EMC Directive are fulfilled.
ETSI produces European standards for EMC for a wide range of information and communication technologies.
The EN 301 489 series of standards specifies relevant EMC requirements for radio communications equipment, and several parts of this series have been updated to take account of the additional technical requirements of the Automotive EMC Directive. Of particular note:
EN 301 489-1 (general EMC requirements for radio equipment)
EN 301 489-7 (specific EMC requirements for GSM terminals)
EN 301 489-24 (specific EMC requirements for IMT-2000 CDMA Direct Spread (UTRA) terminals)
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.
The following is a list of recently published and frequently downloaded standards. Please use the ETSI Work Programme to find further related standards.
|Standard No.||Standard title|
|EN 301 489 series||ElectroMagnetic Compatibility (EMC) standard for radio equipment and services|
|EG 202 414||Guide to the demonstration of conformity for after market Electric/electronic Sub-Assemblies (ESAs) to the motor vehicle EMC Directive 2004/104/EC|