Energy-Saving Glass Loading Dual-Band Miniaturized FSS for RF Shielding With High Oblique Stability and Optical Transparency

In this article, an energy-saving glass with a dual-band miniaturized element frequency selective surface (MEFSS) to enhance the electromagnetic shielding performance while maintaining high optical transparency is proposed, which can reduce interference from wireless communication devices. The reflection bands are located near 2.4 and 3.5 GHz, commonly used by mobile devices for Bluetooth, Wi-Fi, and LTE. This MEFSS has angular stability from 0°–80°, the dimension of which is 0.096 λ 0 × 0.096 λ 0 . The widths of both reflection bands meet the operating demand as the angle of incidence reaches 80°. The shielding effectiveness (SE) is better than 36 dB under normal incidence, and the optical transparency is about 86%. The equivalent inductances and capacitances in the equivalent circuit model (ECM) are obtained based on the electric and magnetic field distributions, and the results calculated by the ECM are consistent with those of the full-wave simulation. In addition, the prototype is fabricated and tested for validation. It provides more than 21 dB band stop responses in 2.4 and 3.5 GHz bands. Furthermore, the test results and the simulation data agree well when the incident angle reaches 70°. The SE in the operation bands exceeds 10 dB for TE and TM polarizations, as the incident angle varies from 0° to 70°.