Shielding Effectiveness

Shielding effectiveness, expressed in decibels (dB), gauges how effectively a shield performs by logarithmically comparing the energy levels on either side of it. A higher dB value signifies better shielding effectiveness.

HOW IS MEASURED

A prevalent approach, as defined by the IEEE 299-2006 standard, employs a self-generated RF signal for testing. The calibration phase involves setting up a transmitting and receiving antenna with no obstruction between them and recording the received signal level. Subsequently, the receiving antenna is repositioned to the same distance but within a shielded enclosure. The signal level is measured again, and the variance between the two readings represents the shielding effectiveness, typically expressed in decibels (dB).

Measurements are taken based on customer specifications or according to the main standards listed below:

• IEEE 299.1 2006
• IEEE 299.2 2013
• CEI EN/IEC 50147-1
• CEI EN/IEC 50147-2
• CEI EN/IEC 61000-5-7
• MIL-STD-188-125-1
• MIL-STD-188-125-2