Excellent angular and electrical performance damage tolerance of wave-absorbing laminate via gradient A-T-A design

Besides broadband electromagnetic wave absorption, electrical performance damage tolerance should be designed and evaluated to compete with advanced detection technologies. In this work, an A-T-A (absorption-transmission-absorption) design strategy with gradient electromagnetic parameters is proposed to enhance angular and electrical performance damage tolerance of wave-absorbing laminated structure in 6-18 GHz frequency band. The quartz fiber cloth with 700 mu m periodic inter-bundle pores served as a transmission layer and was embedded into Fe3Co7/epoxy resin magnetic absorption film to improve the maneuverability of input impedance. Meanwhile, Fe3Co7 with a particle size between 10 and 30 mu m can easily enter the inter-bundle pore to form periodic pattern, enriching the electromagnetic loss mechanisms. Two significant electromagnetic resonance peaks for the designed 5.3 mm thick gradient A-T-A laminated structure occur in the vicinity of 7 GHz and 15 GHz, realizing reflection loss less than -10 dB at an incidence angle of 0-40 degrees in TE mode. When the penetrating damage area accounts for 20 %, effective absorption bandwidth almost covers 6-18 GHz. Therefore, gradient A-T-A structure provides an insight for realizing excellent angular and electrical performance damage tolerance.