Nesting isn’t just for Birds, Nested Enclosures Help to Determine Shielding Effectiveness!Randy Mitchell
The determination of the Shielding Effectiveness (SE) of a material at high frequencies/small wavelengths can give large variations in results based on the testing method employed. One of the methods used to get more consistent results is to use a “nested” testing chamber, meaning a testing chamber is divided by a shielded wall across the middle of the chamber, with a window/hole in it. On the receiving side, there is no mode stirring and the antenna is set up to receive the maximum amount of signal passing through the window. On the transmitting side, a mode stirrer is utilized to create a signal that is directed through the empty hole in the center wall, giving a “control” result illustrating NO Shielding Effectiveness whatsoever. The Device Under Testing (DUT) is placed in the window, sealed with a Shielded Gasket, the transmitting side transmits again and the receiving side takes the measurement of the RF that got through the DUT to the receiving antenna. The difference between the control measurement and the DUT measurement gives a value for the SE of the device under test.
This type of testing is done on many components used in many electronic products, among the standards tested are the IEEE-299 and ASTM E1851-15 which are used to measure the Shielding Effectiveness of electromagnetic shielding enclosures. Our soft-sided reverberation enclosure with metalized textile stirrer is an ideal testing enclosure that can be separated with a center shielded wall in order to provide increased DUT flexibility and a statistically uniform field. This innovation results in more accurate, faster Shielding Effectiveness testing of devices including cable shields, shielding gaskets, shielded components, and the metalized textiles VTT uses to fabricate their RF Shielded Testing Enclosures. V Technical Textiles, Inc.’s portable RF Shielded enclosures provide lightweight shielding solutions in the automobile, military, and the aerospace industries to protect the precise electronic devices used in these fields. Contact us if you need help in your pre compliance emission and susceptibility testing and for lightweight, flexible conductive textiles for your shielding needs!
V Technical Textiles, Inc.
Nested Testing Chambers Metalized Signal Stirrer VTT’s Reverberation Chamber