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EMC GENERAL INFORMATION

2 EMC REGULATIONS

Regulations are one of the primary reasons we test products for EMC. Therefore, we will now

look at some of the important organizations that develop and enforce EMC regulations. Failing

to comply with EMC regulations can result in forced removal of a product from the market

place or even monetary fines.

Figure 3. Conducted versus radiated Regulations

EMC regulations cover the entire spectrum of electrical products, from computing equipment

to microwave ovens to aircraft. As shown, the frequency ranges of interest for EMC testing ex-

tend from 30 Hz to 40 GHz (9 orders of magnitude), depending on the agency and the type of

measurement. The frequency range over which regulations exist varies, depending on the de-

vice and its intended use.

While individual EMC requirements vary widely from one another, one common aspect is the

goal of achieving valid, repeatable results. Therefore, most regulations specify the test envi-

ronment, receiver and transducer characteristics. Antenna height and polarization is usually

varied, and the tested equipment is rotated to find the maximum response from the device. All

these actions help insure that the worst-case emissions are found.

Because so many factors affect emissions, an environment with known characteristics must

be used when measuring electromagnetic interference. Testing within a known environment is

critical in order to assure meaningful and repeatable results that can be compared to other

measurements performed on other devices.

VR02102C

MIL-STD

30 Hz

40 GHz

EN

9 kHz

1 GHz

FCC

30 MHz

40 GHz

MIL-STD

450 kHz

30 MHz

30 MHz

9 KHz

EN

FCC

FCC

Federal

Communications

Commission

EN

European Norms

MIL-STD

US Military

Norms

Frequency (Herz)

CONDUCTED

RADIATED

1 Hz

1 kHz

1 MHz

1 GHz

30 Hz

40 GHz