EMC/EMI measuremnt requirment

[snkhan]

how to differentiate between Radiated Emission/Conducted Emission, Radiated Immunity/Conducted Emission etc.

can these measurement be performed without anechoic chamber.

 

[enjunear]

Typically the four modes of EMI/EMC are Radiated Emissions (RE), Radiated Susceptibility (RS), Conducted Emissions (CE), and Conducted Susceptibility (CS).

All of the tests need to be performed in EMI shield rooms. CE and CS are tests performed on the wires going into/out of the UUT (Unit Under Test). Generally, the CE test measurements are done with LISNs (Line Impedance Stabilization Networks). CS tests are generally done with magnetic loops for injecting current onto cable bundles.

RE and RS are done in shield rooms, typically without dampening materials on the walls, so you don't attenuate the field strength near the UUT unnecessarily. Same goes with Radiated Emissions... you don't want the carbon-loaded tiles soaking up radiated emissions, that would lead to a false-positive result.

If this testing is being performed against some EMI/EMC standard, then the standard should call out proper test environments, and equipment types. You could also reference any handbooks that accompany the EMI/EMC test standards.

 

[snkhan]

does this mean that a shield anechoic chamber fulfill both EMI/EMC testing requirement.

 

[SSCheng]

Hi SNKhan, yes, if you have shielded anechoic chamber, basically it will fulfill both EMI/EMC testing requirements in terms of test sites. However, to fulfill standards' requirements, it also requires some other requirements such as the size of the chamber, environmental conditions, etc. For conducted EMI/EMC it only requires shielded enclosures, but not necessarily anechoic chambers. Radiated EMI/EMC testing will need anechoic chambers, or, OATS (Open Area Test Site) for radiated emissions testing optionally. Let me know if you need further information. Hope it helps.