High-Frequency Estimation of Shielding Effectiveness Without Inner Sensor in Reverberation Chambers

The purpose of this article is to present a new method for measuring the shielding effectiveness (SE) of enclosures without the use of an internal sensor. This technique uses a reverberation chamber (RC) and relies on the ability to accurately estimate the Q-factor as a function of frequency under different load conditions using an electromagnetic absorbing material. This material is placed successively in the RC, outside and inside the shielded enclosure under test (EUT). Based on the contrast of the Q-factor estimates, it is possible, in a noninvasive way, to characterize the SE of the EUT, using an energy conservation approach. The dynamic range of measurements is assessed. Experimental results are provided. It validates the principle and confirms the estimated dynamic range.