Auto-activated Electromagnetic Shield Upon High Intensity Radiated Field Illumination

Abstract

This paper concerns the protection of electro-optic and electromagnetic sensors embedded into a metallic cavity equipped with a window made of a non-electrically conducting material and optically transparent over the visible light and/or infra-red spectrum. In the presence of high intensity radiated fields, the cavity must be appropriately shielded to protect those sensors, this protection being detrimental to EM sensors sensitivity in their absence. We propose here an automatic and quasiinstantaneous activation of an electromagnetic shield printed on the window glass through the detection of the impinging electromagnetic field. The presented solution is based on thin micrometric mesh-metal film deposited on a glass substrate surrounded by a parallel arrangement of p-i-n diodes polarized by the EM field source itself. An experimental validation is performed using a reverberation chamber to generate the electromagnetic field stress while performing a shielding effectiveness measurement using the nested reverberation chamber test setup.