Shielding Effectiveness and HPM Vulnerability of Energy-Saving Windows and Window Panes

In this paper, we report results from shielding effectiveness measurements on energy-saving windows and individual, coated window panes of different generations, as well as results from high-power microwave irradiation on single panes. Shielding effectiveness was measured with two complementary methods: first, with near isotropic irradiation in nested reverberation chambers, and the other with irradiation at normal incidence in a semianechoic chamber. The measurements show that the construction of the energy conserving windows has a clear impact on how well they attenuate radio frequency signals. The more modern the window or pane, the higher is the shielding effectiveness. The high-power irradiation on coated panes showed that depending on the type of coating, hotspots can build up causing the coating to crack and, hence, deteriorate the shielding effectiveness. These results may serve as guidance when reviewing high-altitude electromagnetic pulse (EMP), high-power microwave, or intentional electromagnetic interference protection of critical infrastructures, and provide assistance in the work with reduction of compromising emanations.