Study on frequency selective/absorption/reflection multilayer composite flexible electromagnetic interference shielding fabric

Three kinds of electromagnetic functional materials, frequency selective surface, carbonyl iron coated absorbing fabric and conductive woven fabric, were laminated to filter, absorb and reflect electromagnetic waves. Through equivalent circuit analysis, the frequency selection characteristics and the correlation between the shape and size of the periodic structure of cross-shaped and Jerusalem-shaped frequency selective surfaces were studied. It is found that frequency selective surfaces can reduce the transmission coefficient of carbonyl iron coated fabric at the resonance point, so that the working frequency band of the composite shielding material can be controlled and adjusted. The stacking order has no effect on the frequency selective surface/frequency selective surface double-layer materials, but influence the transmission coefficient of composite materials with frequency selective surface superimposed carbonyl iron coated fabric and/or conductive woven fabric. Among all samples, the transmission coefficient of Jerusalem-shaped/carbonyl iron coated fabric-3/conductive woven fabric has the most strong shielding effect, which is up to -51.72 dB at 10.48 GHz. It is proved that using flexible fabric as the matrix and compounding materials with different electromagnetic functions is an effective method to realize high efficiency and adjustable electromagnetic shielding ability.