Overview of the Civilian and Military EMC norms

Preamble . As briefly described.in our introductory Article N°1 (Issue #2-2015 of EE Magazine), ElectroMagnetic Compatibility is both a functional neccessity – equipments must operate in their intended environment without being disturbed nor causing disturbances to other devices- and a society requirement: interfering with radio/TV broadcast, radio-communications and other RF services is illegal and punishable by laws. Since consumers cannot be easily prosecuted as guilty for using an equipment that is causing interference, the most efficient way of controlling this EMC situation is to apply stringent limits to manufacturers, such as the products they put on market will “never” (exceptional situations accounted) cause interference.

The Ten Commandments for EMC, part 4

EYE ON . It is relatively easy to achieve good attenuation (> 80 – 100 dB) of electromagnetic fields using a compact metal shield. In most practical cases, the shield is not complete, there are almost always openings, i.e. slots, windows and apertures. It is mainly these imperfections in the shield that determines the overall shielding effectiveness of the box.

The first 10 years of EMC work for the JAS 39 Gripen Fighter Aircraft

The new version . of the JAS39 Gripen fighter is now a strong competitor in the fighter aircraft world market and the aircraft operates in several countries. A historical review of the early EMC work for the Gripen project may be of interest. The JAS 39 Gripen fighter aircraft project was outlined and presented in 1979-1981 by SAAB Military Aircraft & The Industry Group JAS also including the Ericsson Microwave Co. and Volvo Flygmotor. The development of the Gripen system and a production of 30 aircraft for the Swedish Air Force was decided by the Government in 1982. The decision was made after an intense debate in the media whether Sweden had the competence and capability to continue the independent fighter aircraft development although such projects had become extremely complex and costly.

Tactical Consequences of Radio Spectrum Out-of-Band Properties

Tactical communications . for ground-based operations requires many co-located communication systems on combat vehicles. Typical frequency bands for such communications are the 30–88 MHz band for army combat radio and the harmonized NATO band 225–400 MHz. As a result of increasing demands of different communication services and larger bandwidth, the amount of co-located communication systems in these bands is continuously increasing. A consequence of this is that the used frequencies will be less separated, meaning that out-of-band properties will be of severe importance for the performance of the individual systems.

Who has the current lead in EMC?

An editor’s reflections . The EMC area has evolved in different directions since it was born about hundred years ago. From the beginning, the driving force was concerns about unintentional interference from electronics and how such interference might affect the new public radio broadcasting services.

The Ten Commandments for EMC, part 3

EYE ON . Shielding is one of the concepts associated with EMC. Often, for example, mechanical engineers are tasked to build a shielding box, without further specification of ie operating frequencies or desired attenuation.
How much attenuation is reasonable to expect?

Background and Comments on the EMC Performance of Cable Trays

The study . “On the EMC Performance of Cable Trays” started with a contact between EMC Services and the Defem company. Their problem was that their design had been given a lot of criticism in the standard EN 50174-2:2000 (on page 25). The standard was found to contain a lot of formulations on EMC, but there was no rationale for the text – nor were they complete.

On the EMC Performance of Cable Trays

How to . improve EMC performances of cable installations. The major conclusion from the study is that cable trays are an integral part of the ground structure (actually, it forms the ground if correctly done; nothing else is needed), which can perform as a shielding structure for the enclosed electronic systems. The major quality parameter […]

WHAT IS EMI/EMC?

Michel Mardiguian . Electro Magnetic Interference (EMI) is the generic term describing a situation whereas an electrical disturbance generated by a certain electronic/electrical equipment is causing an undesirable response to another equipment. This undesirable effect may range from a mere nuisance to a catastrophic failure, with associated financial losses or eventually human casualties. The origin of the disturbance could also be a natural phenomena like lightning strokes or ElectroStatic Discharges (ESD). ElectroMagnetic Compatibility (EMC) is just the opposite: EMI being the disease, EMC is the cure, that is the discipline analyzing and preventing or fixing interference problems.

The Ten Commandments for EMC, part 2

EYE ON . One fundamental concept in EMC design is zoning. Zoning is easy to understand. It is used in the most varied contexts and situations. Situations covering everything from old communist dictatorships, such as for example the former East Germany (DDR), to city planners and the European Union. Zones are used in order to achieve various properties in demarcated geographic areas, or within volumes. Zoning with application in electronic engineering are also known as the Controlled Electromagnetic Topology.

Electronic Environment

For the Electrical Environment since 1994