The proliferation of electronic devices in the world has caused electromagnetic interference (EMI) and radio frequency interference (RFI) to become important concerns.
- NSA 65-6
- IEEE 299
EMI shielding has become a more significant issue due to the increased use of plastic housings for electronic equipment.
EMCTEST performs shielding Effectiveness, Reflection & Scattering Testing.
EMCTEST performs shielding effectiveness, penetration depth, reflection and scattering testing on various materials. We have tested numerous materials used for cellular phone tower aesthetics. We have designed automated fixtures for various test materials from DC to 220 GHz. EMCTEST conducts Shielding Effectiveness testing to the following standards:
Attenuation is one of the principal indicators for measuring the effectiveness of electromagnetic interference shielding.
It refers to the difference between an electromagnetic signal’s intensity before shielding and its intensity after shielding.
When a given electric field strength impinges on a shield barrier at a particular frequency, the wave current is induced into the barrier. This current is reduced by the barrier's skin effect as the wave penetrates the barrier. The ratio of the wave that penetrates the barrier and the incident wave on the barrier is the Shielding Effectiveness of the barrier.
Penetration depth is equal to the reciprocal of Shielding Effectiveness.
Reflection occurs when part of an electromagnetic incident wave that impinges on a material surface returns to its original source.
Scattering occurs when a transmitted wave encounters one or more discrete objects, a rough boundary between two mediums, or continuous irregularities in the complex permittivity of the encountered medium.