Design of a double-layer electromagnetic shielding door for 10 kHz to 18 GHz

We designed, fabricated, and verified a double-layer shielding door with high shielding effectiveness (SE) using a conductive thin-fabric from 10 kHz to 18 GHz. The double-layer structure was studied through analytic and numerical calculations. The study clarified the relationship between the double-layer gap and operating frequency, identifying the frequency range that induces performance degradation. Moreover, it confirmed that the double-layer structure is more effective than a thick single-layer material in the view of implementing high SE. We designed and fabricated a double-layer shielding door using a conductive thin-fabric. The fabric-to-fabric gap was adjusted using the thickness of the metal frame and foam gaskets in the middle layer. It was designed to be 5 mm, which is less than the half-wavelength at 18 GHz. The SE measurement for the door was conducted following standards based on operating frequency ranges. The SE of the double-layer shielding door met the MIL-STD-188-125-1 requirements (over 80 dB up to 18 GHz). This paper demonstrated that the double-layer shielding door using a conductive thin-fabric can provide an alternative shielding solution for infrastructure facilities.